Download Science 10th grade LEARNING OBJECT Do species evolve

Science 10th grade
LEARNING UNIT
How are the components
of the world related?
LEARNING OBJECT
Do species evolve rhythmically or gradually?
S/K
Skill 1. Define the concept of “phyletic gradualism”
Skill 2. Explain the basis of the process of speciatio.
Skill 3. Analyze the theoretical foundations of
mosaic (or modular) evolution.
Skill 4. Clarify that evolution is a process occurring
in the geological time scale (millions of years)
Skill 5. Research into the theory of the common
ancestor.
Skill 6. Look into the contributions of Gould and
Eldredge to the development of the theory of
punctuated equilibrium.
Skill 7. Compare the bases of gradualism and
punctuationism.
Skill 8. Use connectors to express consequence,
cause-effect and comparison-contrast, as a tool to
review studied topics.
Language
English
Socio cultural context
of the LO
Curricular axis
Colombia
Standard
competencies
Explain biologic diversity as a consequence of
environmental, genetic and dynamic-relationship
changes inside an ecosystem.
Background
Knowledge
DNA synthesis, Mendel´s laws, modern genetics,
human ecology, hereditary laws.
English Review topic
Connectors for consequence, cause-effect and
compare-contrast
Vocabulary box
Chromatids: One or two identical chromosomal
strands into which a chromosome splits
longitudinally preparatory to cell division.
Living Surroundings
Idle: Not working or active; unemployed; doing
nothing.
Lineage: The line of descendants of a particular
ancestor; family.
Polyploid: Having a chromosome number that is
more than double the basic or haploid number.
Vestige: A mark, trace, or visible evidence of
something that is no longer present or in existence.
Wisdom Teeth: The third molar on each side of the
upper and lower jaw: the last teeth to erupt.
NAME: ______________________________________________________________
GRADE: _____________________________________________________________
Objectives
• To analyze the theory of punctuated equilibrium in the context of evolution
of biologic species.
• To explain how evolution occurs based on different theories and its
implications for speciation, taking into account the theory of a common
ancestor and the contributions done by Gould and Eldredge regarding
gradualism and punctuationism.
• To reflect on the effects of different evolutionary theories in the conception
of the human being.
• To give advice in a classroom conversation about studied topics.
Introduction
The human body has evolved for millions of years and during this period it has
developed abilities that allow it to adapt to the environment. Some parts of the
human being have deteriorated or degenerated until losing the original purpose
they had, therefore, these organs or structures are not vital any longer, becoming
useless, and are at risk of disappearing. Charles Darwin called these processes
“vestiges” because they are evidence of evolution.
A clear example of this are wisdom teeth, crucial for chewing branches or bones
millions of years ago, but, nowadays, they are unnecessary due to changes in
nutrition of humankind. The same situation occurs with the appendix, an idle
organ used to digest cellulose when the dietary base of humans relied on plenty
vegetable proteins.
Similarly, the pinky finger in the feet gets smaller on every generation and there
will come the time, in millions of years, when it will disappear completely. The only
certain thing is that the only truly essential toe is the thumb because it helps to
maintain the balance of the entire body. Additionally, hair was useful for humans
to isolate cold, but it began regressing progressively to guarantee better
temperature regulation. However, hair continued to grow on different parts of the
body, such as eyebrows, to avoid sweat drip into the eyes and to express
emotions, and in the beard as a factor in sexual selection. However, most of the
hair that covers the human body does not have a specific function.
Then, why do we change? How do we evolve? Why do some individuals do not
present these characteristics, such as wisdom teeth? Where do you think these
micro-changes will lead us?
ACTIVITY 1
- SKILL 1: Define the concept of “phyletic gradualism”
- SKILL 2: Explain the basis of the process of speciation.
- SKILL 3: Analyze the theoretical foundations of mosaic (or modular) evolution.
- SKILL 4: Clarify that evolution is a process occurring in the geological time scale
(millions of years)
INTRODUCTION
According to Ayllón (2011):
The evolutionary theory developed by Charles Darwin suggests that living
creatures change with time, and different degrees of relationships appear
between species; reason why Darwin proposes natural selection as the motor of
evolutionary change, but only the fittest individuals are capable of producing
offspring. Evolution is evidenced by fossil register and genetic kinship.
Campo, (2013), states that:
Living creatures came to be 4000 million years ago, as bacteria that multiplied
and diversified into billions of species, which resulted in the generation of species
with progressive complexity in the course of time. Thus, evolution is a fact that
can be proven with evidentiary support, but the exact mechanism how it happens
is not fully understood, because it is unclear if the formation of new species
happens slowly and gradually or in sharp leaps. What is known, however, is that
evolution is a continuous process of adaptation to the environment.
For example, mankind has evolved as shown in the following timeline, which
shows the physiological changes that helped them adapt to the environment.
4 million
First
Hominids.
The oldest
fossils found –
belonging to
the
Australopithec
us- are four
million years
old. They are
not complete
skeletons but
isolated
remains.
3,6 million
New fossils
have been
found at
Sterkfontein
caves, in the
outskirts of
Johannesburg.
The oldest
skeleton.
The remnants
found in South
Africa belong to
the
“Australopithec
us Africanus”
species. Around
1,20m in height
and a brain
slightly bigger
than a
chimpanzee’s.
AUSTRALOPIT
HECUS
AUSTRALOPITH
ECUS
2,5 million
1 million
150000
The first
humans.
The oldest
vestiges of
the Homo
genre,
characterized
by a brain
bigger than
the
Australopithe
cus; they
appeared
around the
same time
than the first
stone tools.
Humankind
expands.
Although
some
scientists
state that
“Homo
Erectus”
appeared in
Africa 1.8
million years
ago, there are
no concluding
proofs beyond
one million
years ago.
“Homo
Sapiens”.
According to
most experts,
the current
species
appears in
Africa only
150000 years
ago and then
travels around
the Earth.
HOMO
HABILUS
HOMO
ERECTUS
HOMO
SAPIENS
ANAMENSIS
AFRICANUS
Retrieved from: Soy así por la ciencia, no por la moda: http://www.taringa.net/posts/cienciaeducacion/17186065/Soy-asi-por-la-ciencia-no-por-la-moda.html
Different ways of evolution enable the appearance of new species, known as the
“Compound of populations whose individuals are potentially capable of
reproducing among them naturally and are isolated, reproductively, from other
groups” being their offspring fertile. (Israel, 2013).
However, starting from existing species, new lineages can appear, producing new
species in a process called speciation. This process is defined as the cause that
allows a determined species to generate a different population, reproductively
isolated from the previous one, which gradually develops genetic differences,
showing diversity.
According to Abarca (2011), there are different speciation processes that can be
classified as:
- Geographic or allopatric speciation: This process occurs when a population
with similar genetic characteristics founds itself isolated by a geographic accident,
such as rivers, mountains or deserts, which leads to the formation of geographic
races which in turn produce new species who do not exchange genes, evolving
separately. .
For example, species of rabbits were separated and isolated reproductively by the
presence of a river.
Modified from: Neodarwinismo, o la relación entre evolución y genética: http://b-logia20.blogspot.com.co/2015/02/neodarwinismo-o-la-relacion-entre.html
- Sympatric speciation: This type of speciation refers to genetic changes in
populations that inhabit one geographic region, but segregate into different
species due to the appearance of diverse mechanisms of reproductive isolation. .
For example, genetic changes in populations can isolate them in reproductive
terms.
- Parapatric or polyploid speciation: This type of speciation refers to an
increase in the number of chromosomes in an organism of the population. This
individual does not reproduce with other members of the group, but only with
others that share its polyploidy, which is the heritable condition of possessing
more than two complete sets of chromosomes. This phenomenon occurs most
commonly in less evolved animals and vegetables.
Modified from: Especiación en plantas: http://www.genomasur.com/a_evo/evo_43_p.htm
Increase in the number of chromatids in the Anemone flower, separating the
species reproductively.
There are different theories regarding evolution. Some of them are:
1). Phyletic evolution, anagenesis or phyletic gradualism: According to
Guammen (1996), “Refers to changes in species through soft and continuous
processes in time. As a consequence, species do not exist as well defined units,
but as groups in constant modification, presenting infinity of intermediate stages
for each species, called links”
As such, progressive evolution of species implies a change in the genetic
frequency of the entire population and by processes of mutation, allows significant
differentiation from a previous generation, creating a new species and rendering
the former generation extinct. For this reason, Ermini (2011) states that “a
species changes gradually with time, until becoming a species that looks and acts
differently”
Consequently, characteristics of phyletic gradualism can be summarized as: 1)
New species are originated by the transformation of an entire previous population.
2) This transformation is slow and consistent. 3) The transformation affects a high
percentage of the population, generally the entire group. 4) Finally, the
transformation covers a vast part of the geographic distribution of the previous
generation.
Did you know?
Evolution of fingers and teeth of horses fits inside the evolutionary theory of
phyletic gradualism and can be followed through its ancestor Hyracotherium (also
called Eohippus). A small mammal ranging in size between 20cn and 40cm tall,
herbivore that lived during the Eocene, 55 million years ago, in North America,
with four fingers in the forelimbs and three in the hind limbs, each one ending in a
nail.
Its changes were evidenced in the increase of its height up to 115cm and loss of
fingers until becoming monodactyl, meaning with only one finger. Little by little,
its only finger hardened until developing hooves to be able to run away from
predators. Regarding its teeth, Merychippus developed dentures with high crowns,
which enabled it, as opposed to Hyracotherium, to scavenge leafs and stumps in
trees and shrubs. That is how Hyracotherium became extinct and genetic
transformation opened the path for Equus, known as the current horse, as
illustrated in the figure. [CITATION Bul11 \l 9226].
For example, evolution of fingers and teeth of horses, as shown in the following
image:
Retived from https://upload.wikimedia.org/wikipedia/commons/d/dd/Horseevolution.png
2). Punctuated equilibrium or punctuationism: Cachón & Barahona (2013),
conceive speciation “as a quick transformation of peripheral populations,
presenting long periods of stability, that appear punctuated, or interrupted, by
brief moments of quick evolution, producing visible transformations and new
species based on existing ones. This explains why the absence of intermediate
steps in the fossil registry does not mean it is incomplete, but sometimes
evolution advances quickly”
This concept was suggested by Eldredge and Gould, two paleontologists of the
United States of America, based on observations of fossils with few or null
changes in each species found.
Available fossil tests propose that several lineages seem to follow the same
evolutionary pattern, called saltationism, which is a sudden change of a big
magnitude, produced between one generation and the next, turning saltation as a
mechanism of speciation. The extraordinary diversity of life is explained by the
fact that species change and are divided by leaps, and not gradually.
Retrieved from: Las bases genéticas de la evolución:
http://cienciasteorias.blogspot.com.co/2011/07/evolucion-las-bases-geneticas-de-la.html
In the previous image, the organisms that represent this model are cichlid African
fish from Lake Victoria. This lake, which is less than 1 million years old, has around
two hundred species of cichlid fish, of different sizes and shapes, adapted to the
diverse habitats and nourishment types available in the lake. According to
existent data, this compound of species evolved from one unique ancestor that
existed only 200000 years ago.
3). Mosaic (or modular) evolution: Tarancón (2013) suggests that “certain
structures possess a rate of evolution or modification greater than the rest of
structures of the same individual. This is why these individuals may preserve
structures from their ancestors but at the same time incorporate new ones. Thus,
evolutionary changes do not necessarily affect the entire organism at once, but
may vary the anatomy of some of its parts.”
The occurrence of these types of changes is random, without defined direction or
purpose, but always controlled by natural selection. Because there are different
ways for an anatomic change to occur, more than one can appear simultaneously,
adding the effects towards the final morphologic change. This results in an
evolutionary pattern where all the characteristics of an organism evolve at the
same rate. The pioneer of this theory is Gavin de Beer. [CITATION Riv07 \l 9226].
For example, the social, cultural, learning, physiological and neurological aspects
were not linked when language started, but intellectual development and the
ability to connect them in a unique system progressed, resulting in a more useful
and effective communication mechanism without modifying the volume of the
brain.
Learning Activity:
- SKILL 1: Define the concept of “phyletic gradualism”
- SKILL 2: Explain the basis of the process of speciation.
- SKILL 3: Analyze the theoretical foundations of mosaic (or modular) evolution.
- SKILL 4: Clarify that evolution is a process occurring in the geological time scale
(millions of years) SKILL 7: Compare the bases of gradualism and punctuationism.
- SKILL 8: Use connectors to express consequence, cause-effect and comparisoncontrast, as a tool to review studied topics.
The following exercises expect to establish relations between the concepts
covered in the unit and mental construction developed by the students to explain,
understand and interpret the process of evolution.
1. Look carefully for the following words in the Word Search. Once you finish,
complete the paragraph explaining the process of evolution according to the
period of time.
Millions
Long
Environment
Allopatric
Soft
Need
Short
Speciation
Independent
Continuous
Adaptation
Origin
Geographic
Evolution
Population
Change
individuals
Barriers
Species
Phyletic
Time
Vegetation
Transformations
Phyletic
Gradualism
Fill in the gaps:
Life began 4.50 _______________ of years ago, and has since transformed and
evolved in the course of ______________, thanks to a _____________ of
________________ to ____________ in the ____________ or the _______________. These
changes are expressed in a ____________ or ___________ period of time, resulting in
the ___________ of new __________________ which generate new ____________, that in
turn, because of ____________ ________________ and genetic ______________ are
separated, generating __________________.
2. Watch carefully the next video, and then define speciation and the basis of the
process of speciation in one paragraph.
Video: Especiación: https://www.youtube.com/watch?v=1hHlvvcAkzE
___________________________________________________________________________________
___________________________________________________________________________________
___________________________________________________________________________________
3. According to the information developed so far in the unit, and considering the
context of the following paragraph, explain the meaning of the underlined
phrases.
"Natural selection can happen only through preservation and accumulation of
infinitely small modifications, each of them destined to preservation of life, the
process of modification and production of a number of related forms must be slow
and gradual, -a species originates at first two or three varieties, these begin to
transform into species slowly, which, in turn, produce other species in equally
slow steps”.
“It is a very important consideration, because the periods during which these
species have suffered modifications are extremely long to be measured in years,
but are relatively short in comparison to periods in which species have remained
without suffering any change at all”
Retrieved from: García and others (2002).
3.1. “the process of modification and production of a number of related forms
must be slow and gradual”
3.2. “species have suffered modifications”
4. Watch carefully the following video. Based on the information shown, organize
the following sentences inside the table, so that similarities and differences
between the concepts of gradualism and punctuationism are expressed.
Video: Gradualism vs. Puntuacted Equilibrium: https://www.youtube.com/watch?
v=qWUqQyVa5ts
- Changes occur in long periods and are punctuated in time.
- Changes occur in short periods and in leaps in time.
- Produces small changes
- Produces big changes.
- Slow evolution
- Quick evolution
- There is evolution through time
- Changes appear because of pressure in the environment
- All organisms descend from a common ancestor .
Gradualism
Punctuationism
Differences
Similarities
5. Mosaic (or modular) evolution states that there are certain structures with a
higher rate of evolution or modification than the rest of the structures of the same
organism. Research at least three examples of any type of living organism on
Earth, where mosaic evolution can be evidenced. Once you have identified the
examples, choose the most relevant of the three and build a 3D model, as well as
an oral presentation that must not exceed 5 minutes, in which you must analyze
the theoretical bases of this type of evolution.
Language practice
In pairs, fill in the gaps using the appropriate connector from the box. Remember
you can give advice to your classmate during the exercise using the expression “If
I were you”, for example:
Student A: I think the best answer for number 1 is…
Student B: If I were you, I’d choose…
Furthermore
Consequently
On the
Contrary
Consequently
But
1. Charles Darwin suggests in the development of the theory of evolution that all
organisms change in time ________maintain degrees of relationship among them.
2. There are different theories about the mechanism species use to evolve,
__________ they all share the idea that all of them originated from already existing
species
3. There are different types of speciation, such as geographic speciation, which
occurs when a population of the same species is separated from another one by a
geographic accident. They must evolve independently, and ___________ reproduce
in isolation.
4. Among evolutionary theories, we can find phyletic evolution, presenting soft
and continuous variations in populations through time._____________, species do
not exist as well-defined units, ________ as groups in continuous
modification.___________, the theory of punctuated equilibrium suggests that
speciation occurs as quick transformations in peripheral populations. ____________,
between one speciation event and the next we can find long periods of balance
that appear punctuated (or interrupted) by brief periods of quick evolution.
Did you know?
Our ancestors had bigger jaws than current humans, which helped them to
maintain a diet based on hard and raw roots, nuts and leaves. That is how wisdom
teeth appeared, a third group of teeth which are believed to be an evolutionary
answer to the nourishment habits of earlier humans. However, with time,
maxillaries have progressively decreased but maintaining the same number of
teeth, and that has become a problem, because the evolution of bones has not
been simultaneous with the evolution of teeth (mosaic evolution), and since
wisdom teeth are the last ones to appear, they do not have a proper place to do
so, thus generating dental issues.
It has been determined that only 10% of the current population does not possess
wisdom teeth, creating a change in their physiology. Probably, after some time, no
human being will have wisdom teeth, due to dietary changes. Therefore, are we
still evolving?
Abstract
Charles Darwin suggests in the development of the theory of evolution that all
organisms change in time but maintain degrees of relationship among them.
According to this theory, only the fittest organisms can reproduce so that some
adaptations to the environment are inherited to their descendants. This process is
lengthy through time and happens in changing environments, resulting in
diversification of species.
There are different theories about the mechanism species use to evolve, but they
all share the idea that all of them originated from already existing species.
Understanding the concept of species as organisms capable of reproduction, who
are reproductively isolated from others, and their offspring is fertile, is the basis to
define speciation as the process when a population of a determined species
makes room for a new one, reproductively isolated from the previous one,
gathering genetic differences throughout time.
There are different types of speciation, such as geographic speciation, which
occurs when a population of the same species is separated from another one by a
geographic accident. They must evolve independently, and consequently
reproduce in isolation. Similarly, we can find sympatric speciation, which happens
in species that diverge by means of reproductive isolation; and parapatric
speciation, which increases polyploidy between individuals, isolating them
reproductively and genetically.
Among evolutionary theories, we can find phyletic evolution, presenting soft and
continuous variations in populations through time. As a consequence, species do
not exist as well-defined units, but as groups in continuous modification. Contrary
to this idea, the theory of punctuated equilibrium suggests that speciation occurs
as quick transformations in peripheral populations. Furthermore, between one
speciation event and the next we can find long periods of balance that appear
punctuated (or interrupted) by brief periods of quick evolution.
A different line of thought is mosaic (or modular) evolution, which states that
certain structures or modules that make part of living creatures possess a higher
rate of evolution or modification than the rest of the structures of the same
organism. These organisms may preserve the same structures as their ancestors
but can also incorporate new ones. However, evolutionary changes do not
necessarily affect the entirety of the organism at once; they can vary the anatomy
of only specific parts of the living creature.
Homework
1. Starting from a single predecessor organism, life diversified in the multiple
forms that inhabit present day Earth; this is known as the common ancestor.
Based on the previous statement, in groups of 4 students, investigate how, when,
where and what represents the common ancestor of all living creatures, as well as
how this organism evolved until now. Once you have the results of your research,
create a timeline showing your results and share them in a presentation no longer
than 10 minutes.
2. In pairs, investigate how the contributions of Gould and Eldredge helped the
development of punctuated equilibrium theory, and present at least two
examples. Once you are finished with your inquiry design a story to evidence
these events and share it with the rest of your classmates.
Evaluation
Based on the topics covered in the unit, the evaluation will assess the
understanding of the materials developed so far.
1. Who proposed the theory of evolution of species?
a) Charles Darwin
b) Niles Eldredge
c) S. J. Gould
d) Alfred Russel Wallace.
2. Which theory suggests that organisms change slowly and gradually?
a) Gradualism
b) Punctuated Equilibrium
c) Neutralism
d) Synthetic Theory
3. Which theory suggests that the origin of new species (speciation) can occur in
short or immediate geological periods, through mechanisms like polyploidy in
plants?
a) Gradualist Theory
b) Punctuated Equilibrium
c) Neutralism
d) Gradualism
4. Which theory suggests that “most species can stay millions of years with
morphology relatively similar and only experiment slight fluctuations with no
apparent direction or purpose?
a) Natural Selection
b) Punctuated Equilibrium
c) Neutralism
d) Gradualism
e) Synthetic Theory
5. Which are the vestigial organs in human beings?
a). Incisor teeth and molars
b). Third molars and liver
c). Liver and appendix
d). Wisdom teeth and appendix
6. Watch closely the following figure and complete the sentence:
A common ancestor is __________________________________. The one who originated
dogs and cats was ___________________, through a type of evolution called
____________________, these species diversified the most in the _________________
era.
Bibliography
Abarca, B. (2011). Biología 26. Retrieved on March 28th, 2016, from
http://biologia26.blogspot.com.co/2011/12/especiacion.html
Ayllón, J. (2011l). La evolución del evolucionismo. Revista cultural y de cuestiones
actuales de la Universidad de Navarra (p. 667).
Bulfon, G. (2011). Taringa.net. Retrieved on March 28th, 2016, from
http://www.taringa.net/posts/info/7218006/Evolucion-Del-Caballo-Equus-feruscaballus.html
Cachón, V., & Barahona, A. (2013). Facultad de Ciencias UNAM. Retrieved on
Match 28th, 2016, from 142-140-1-PB%20(3).pdf
Campo, D. (2013). D Ciencia. Retrieved Marzo 28, 2016, from
http://dciencia.es/que-es-la-evolucion-conceptos/
Ermini, J. (2011). Taringa.net. Retrieved on March 28th, 2016, from
http://www.taringa.net/post/ciencia-educacion/9205456/Tipos-de-evolucion-casosy-medidas-de-evolucion.html
Evolución y Biología Evolutiva. (2011). Retrieved on March 28th, 2016, from
https://otrabiologia.files.wordpress.com/2011/06/evolucion.pdf
García, P., Montellano, M., Quiroz, S., Sour, F., Ceballos, S., & Chávez, L. (2002).
Paleobiología. México: Facultad de Ciencias, UNAM. Retrieved from
http://www.libros.unam.mx/digital/V5/36.pdf#page=241
Guammen, D. (1996). Todo Sobre la Evolución. Retrieved on March 28th, 2016,
from http://todosobrelaevolucion.org.mx/capsula.php?id=50
Israel. (2013). La Evolución sencilla. Retrieved on March 28th, 2016, from
https://laevolucionsencilla.wordpress.com/2013/02/23/capitulo-1-bisprofundizamos-en-la-evolucion-especiacion-como-resultado-de-la-evolucion/
Malena. (2009). El teoguillo.com. Retrieved on March 28th, 2016, from
http://elteologillo.com/2016/02/25/la-teoria-de-los-equilibrios-puntuados/
Martínez, C. (2003). El Clarín. Retrieved on March 28th, 2016, from
http://edant.clarin.com/diario/2003/08/21/s-03901.htm
(n.d.). Retrieved on March 29th, 2016, from
http://portalacademico.cch.unam.mx/alumno/biologia2/neutralismoyequilibrio/equ
ilibriopuntuado
Rivera, Á. (2007). Evolución y conducta. ARQUEOWEB: Revista sobre arqueología
en internet, 1(9).
Rothhammer, F. (1984). Evolución gradual o revolución genética. Revista chilena
de Historia Natural, 57: 5-7.
Tarancón, J. (2013). Geología. Retrieved on March 29th, 2016, from
http://gealogia.blogspot.com.co/2013/04/la-evolucion-en-mosaico.html
Glossary
•
Adaptation: Physiological process or morphological or behavioral trait of an
organism that has evolved during a period by means of natural selection, in order
to increase expectancy in the long term to reproduce successfully.
•
Common ancestor: Living creature or species from which two or more
individuals of a species descends.
•
Chromosomes: Organelle in the form of filament found in the interior of a
nucleus of a eukaryote cell, containing genetic material.
•
Offspring: Offspring, or progeny, is the result of reproduction, which means,
the individual or individuals produced during the intervention of one or more
parents.
•
Genetic Divergence: The result of adaptations and mutations that act on
populations.
•
Diversity: Refers to the ample variety of living creatures on Earth and the
natural patterns forming it, resulting in billions of years of evolution.
•
Speciation: The process in which a population of a determined species
makes room for another population, reproductively isolated from the previous
population, and gathering genetic differences throughout time.
•
Species: The compound of natural organisms or populations capable of
mating and producing fertile offspring, but not capable to do so (or at least not
commonly) with members of populations from another species.
•
Evolution: The change in phenotypic genetic heredity of biological
populations through generations that has originated diversity of living creatures
existing on Earth, from a common ancestor.
•
Gene: Particle with genetic material that, along with others, is found on a
fixed order on a chromosome, and determines the appearance of hereditary
characters in living creatures.
•
Gradualism: The evolution process that occurs through soft and continuous
changes of the populations in time.
•
Mutation: A change in the genetic information (genotype) of a living
creature, producing a variation in the characteristics of the organism and is not
necessarily transmitted to the offspring. It occurs spontaneously and suddenly, or
by the action of mutagens. This change will be present in a small proportion of the
population (variant) or in the organism (mutation)
•
Kinship: The link that joins species that have a common ancestor.
•
Population: The compound of organisms or individuals of the same species
that co-exist in the same space and time.
•
Punctuationism: A theory that determines that during most of the existence
of a species, it will remain stable or presenting minor changes (stasis periods),
gathering evolutionary changes during the process of speciation (formation of
new species), that will result in a species of brief genetic revolution in geological
terms.
•
Natural Selection: A phenomenon in evolution defined as the differential
reproduction of genotypes in a biological population. The classic formulation of
natural selection establishes that the conditions of an environment can be
beneficial or harmful; meaning that reproduction of living organisms is selected
according to their singularities.