Download it did not explain how favorable traits were passed to offspring

NAME
PERIOD
GALE Article Review: Evolution
CTRL + click on the link to the Natural Selection unit in the GALE database:
http://galedc.com/site/medfordscience/science7/49173
Click on the Evolution topic, then click on Evolution Entry 1 and read the
article, responding to these prompts as you read:
Evolution refers to…living things on earth changing over time.
Evolution is one of the most fundamental and important general concepts in all
biology.
Origin of Life
Louis Pasteur showed that living organisms come from existing living things
through reproduction.
Historical background
Explain Lamarck’s idea of inheritance of acquired characteristics: During an
individual organism’s life cycle, traits that are favorable develop, and then are
passed on to offspring, which have these traits. Traits that are not favorable do
not develop, and are not passed on to offspring.
Lamarck was the first scientist to…propose the idea of adaptation..
Alfred Wallace and Charles Darwin provided a mechanism to explain
evolutionary change.
In On the Origin of Species, the scientist concluded that some individuals in a
species are…born with traits that are more favorable in their environment.
1
These individuals are more likely to...survive and reproduce.
Individuals that are not well-adapted are less likely to... survive and reproduce.
Each generation of a population will consist of... a mixture of individuals with
more favorable traits and individuals with less favorable traits
The overall characteristics of the population will change to reflect this better
adaptation to the environment.
The major problem with this theory was… it did not explain how favorable traits
were passed to offspring
Gregor Mendel discovered that...hereditary characteristics are transmitted from
generation to generation in what we now call genes.
Evidence for evolution
Explain how embryology and vestigial features provide evidence
Embryos of all vertebrates have similar structures, which suggests they
developed and changed from a structure in a common ancestor. Vestigial
features were useful in a common ancestor, and are still present, but not useful
in that present organism.
2
Explain how comparing physical structures provides evidence
A homologous structure may be adapted for different uses in various
organisms through divergent evolution, supporting the idea that a common
ancestor had a similar structure.
Explain how fossils provide evidence
Fossils show certain living things were once alive, but not now. Fossils show
changes in traits over time.
Explain how evolution can be observed
Rapid changes in viruses and antibiotic resistant bacteria show that favorable
traits can increase in a population very rapidly.
Explain how DNA provides evidence
All organisms have DNA with the same structure and function, suggesting that
all organisms share a common ancestor with DNA.
3
Evolutionary mechanisms
All muskrats in the population will not have.. identical genes and traits
Explain overproduction and natural selection in a muskrat population:
.There are too many muskrats for the resources in the environment. Some
have a trait more favorable, like thick fur in a cold environment. These
individuals are more likley tol survive, and also to reproduce. Alleles causing
that favorable trait are passed on to offspring. The share of indivduals with
thicker fur will increase over time.
Explain how mutation can create positive changes:
Mutations are random changes in DNA. While most changes have no effect, or
negative effects, some may cause changes in traits that make them more
favorable in a particular environment. If individuals with those traits survive
and reproduce better, they will pass on the mutation in DNA to offspring
4