Mechanisms of Evolution
... Founder Effect: result of migration (Darwin’s finches) Ex. Amish and Mennonites: people rarely marry outside their own communities; Old Order Amish—high frequency of 6-finger dwarfism—can trace ancestry back to one of the founders of the ...
... Founder Effect: result of migration (Darwin’s finches) Ex. Amish and Mennonites: people rarely marry outside their own communities; Old Order Amish—high frequency of 6-finger dwarfism—can trace ancestry back to one of the founders of the ...
speciation - WordPress.com
... The two populations are no longer able to interbreed, due to genetic differences in habitat ...
... The two populations are no longer able to interbreed, due to genetic differences in habitat ...
NCEA Style Question
... Prezygotic: Temporal (eg breed at different times of the year; active at different times of day). Mechanical (genital structure may no longer fit like a lock and key). Behavioural: different mating displays not recognised by the other group. Gamete incompatibility: eg. different number of chromosome ...
... Prezygotic: Temporal (eg breed at different times of the year; active at different times of day). Mechanical (genital structure may no longer fit like a lock and key). Behavioural: different mating displays not recognised by the other group. Gamete incompatibility: eg. different number of chromosome ...
Name - adaptingtotheenviroment
... A. when a species produces many more offspring than can survive B. when plants produce more food than is needed C. when individuals produce more offspring than simply replacing themselves D. when individuals in a species can't get enough food 4. Competition between individuals is usually: B A. direc ...
... A. when a species produces many more offspring than can survive B. when plants produce more food than is needed C. when individuals produce more offspring than simply replacing themselves D. when individuals in a species can't get enough food 4. Competition between individuals is usually: B A. direc ...
Population Change
... Populations can change and diverge when they are isolated from one another. • Speciation is a splitting event that creates two or more distinct species from a single ancestral group. ...
... Populations can change and diverge when they are isolated from one another. • Speciation is a splitting event that creates two or more distinct species from a single ancestral group. ...
The Origin of Species
... cell division extra sets of chromosomes are generated. Occurs in plants species. Autopolyploidy: failure of meiosis results in 4n. Can self fertilize or mate with other 4n’s. Sterile offspring made when fertilize a 2n. Discovered by Hugo de Vries in 1900’s, ...
... cell division extra sets of chromosomes are generated. Occurs in plants species. Autopolyploidy: failure of meiosis results in 4n. Can self fertilize or mate with other 4n’s. Sterile offspring made when fertilize a 2n. Discovered by Hugo de Vries in 1900’s, ...
Speciation
... • Morphological (form) differences can prevent successful mating – Ex. Size and shape of reproductive organs anatomically incompatible Even in closely related species of plants, the flowers often have distinct appearances that attract different pollinators. These 2 species of monkey flower differ gr ...
... • Morphological (form) differences can prevent successful mating – Ex. Size and shape of reproductive organs anatomically incompatible Even in closely related species of plants, the flowers often have distinct appearances that attract different pollinators. These 2 species of monkey flower differ gr ...
Speciation & Macroevolution
... Incompatible structural differences in reproductive organs of similar species ...
... Incompatible structural differences in reproductive organs of similar species ...
Chapter 17
... • Occurs when a species fails to produce any more descendents. ****The species that exist at any time are the net result of both speciation and extinction. -if you think of speciation as like a branch off of a family tree, then extinction is like the loss of one of those branches. ...
... • Occurs when a species fails to produce any more descendents. ****The species that exist at any time are the net result of both speciation and extinction. -if you think of speciation as like a branch off of a family tree, then extinction is like the loss of one of those branches. ...
Chapter 24 ppt
... - If you are really determined • Postzygotic barriers: fertilization occurs, but the hybrid zygote does not develop into a viable, fertile adult • Reinforce Pre-mating factors • Reduced hybrid viability (frogs; zygotes fail to develop or reach sexual maturity) • Reduced hybrid fertility (mule; horse ...
... - If you are really determined • Postzygotic barriers: fertilization occurs, but the hybrid zygote does not develop into a viable, fertile adult • Reinforce Pre-mating factors • Reduced hybrid viability (frogs; zygotes fail to develop or reach sexual maturity) • Reduced hybrid fertility (mule; horse ...
Hybridization and “Genetic” Extinction
... wide variety of plant and animal taxa because of various human activities” (Rhymer and Simberloff 1996) • The positive view: “We conclude that when viewed over the long-term of millenia, introgressive hybridization may have contributed importantly to the generation of species diversity in birds” (Gr ...
... wide variety of plant and animal taxa because of various human activities” (Rhymer and Simberloff 1996) • The positive view: “We conclude that when viewed over the long-term of millenia, introgressive hybridization may have contributed importantly to the generation of species diversity in birds” (Gr ...
Hybridization and speciation in angiosperms: arole for pollinator
... hybrids that have become genetically isolated from their parents and are functioning as distinct evolutionary units, as bona fide species. Hybrid individuals form often [3], but in general are ephemeral, either dying off or being reabsorbed into one of their parental taxa, which leads to introgressi ...
... hybrids that have become genetically isolated from their parents and are functioning as distinct evolutionary units, as bona fide species. Hybrid individuals form often [3], but in general are ephemeral, either dying off or being reabsorbed into one of their parental taxa, which leads to introgressi ...
Mixed Up Species
... protect individual species. Sometimes these barriers are as simple as geography. Animals on one side of a ...
... protect individual species. Sometimes these barriers are as simple as geography. Animals on one side of a ...
Chapter One – Introduction to Primate Studies
... other local populations, begin to evolve separately (through both natural selection in their ...
... other local populations, begin to evolve separately (through both natural selection in their ...
lecture 17 - post-zygotic + hybrids - Cal State LA
... Post-zygotic reproductive isolation Post-zygotic isolation results when hybrid offspring are: - inviable (fail to develop at all) - viable, but infertile (one or both sexes cannot reproduce) Hybrid breakdown is the term for infertility in viable hybrids - many hybrids, like mules, are viable but can ...
... Post-zygotic reproductive isolation Post-zygotic isolation results when hybrid offspring are: - inviable (fail to develop at all) - viable, but infertile (one or both sexes cannot reproduce) Hybrid breakdown is the term for infertility in viable hybrids - many hybrids, like mules, are viable but can ...
When hybrids are fertile - Revista Pesquisa Fapesp
... within cells that contain genes. This difference can prevent the normal development of the embryo, as each chromosome that came from the male parent must be aligned with an equivalent chromosome from the female parent when the fertilized cell divides for the first time. Without this proper alignment ...
... within cells that contain genes. This difference can prevent the normal development of the embryo, as each chromosome that came from the male parent must be aligned with an equivalent chromosome from the female parent when the fertilized cell divides for the first time. Without this proper alignment ...
On gene expression and speciation
... the Swedish islands of Gotland and Öland and established viable breeding colonies. These islands have previously been inhabited by the closely related pied flycatcher (Ficedula hypoleuca) which occurs all over Sweden. The species diverged only one million years ago and are still very similar to each ...
... the Swedish islands of Gotland and Öland and established viable breeding colonies. These islands have previously been inhabited by the closely related pied flycatcher (Ficedula hypoleuca) which occurs all over Sweden. The species diverged only one million years ago and are still very similar to each ...
Evolution Review
... A population of rabbits may be brown (the dominant phenotype) or white (the recessive phenotype). Brown rabbits have the genotype BB or Bb. White rabbits have the genotype bb. The frequency of the BB genotype is .35. • What is the frequency of heterozygous ...
... A population of rabbits may be brown (the dominant phenotype) or white (the recessive phenotype). Brown rabbits have the genotype BB or Bb. White rabbits have the genotype bb. The frequency of the BB genotype is .35. • What is the frequency of heterozygous ...
ChromosomesII - life.illinois.edu
... meiosis is abnormal. Nondisjunction in a meristematic cell --> 36 chromosomes. The cell is said to be allopolyploid (allotetraploid). Normal meiosis! These plants are self-fertile, so can produce offspring, even if there is only one such individual. New “genus/species" was named Raphanobrassica. ...
... meiosis is abnormal. Nondisjunction in a meristematic cell --> 36 chromosomes. The cell is said to be allopolyploid (allotetraploid). Normal meiosis! These plants are self-fertile, so can produce offspring, even if there is only one such individual. New “genus/species" was named Raphanobrassica. ...
Supplemental Table 2: Pre- and Post-Assessment
... different data can lead to different inferences. We used Figure 4 from (26) to illustrate that taxonomy may not align with phylogeny. This question could be adjusted to be more isometric with the preassessment or used to assess skill in reading a phylogeny. ...
... different data can lead to different inferences. We used Figure 4 from (26) to illustrate that taxonomy may not align with phylogeny. This question could be adjusted to be more isometric with the preassessment or used to assess skill in reading a phylogeny. ...
10 - gwbiology
... 10. Species help to distinguish between different types of plants and animals by their difference appearances. Species can be determined by their physical form or structure called morphology, other factors that can determine a species is differentiation in body functions, biochemistry, behavior and ...
... 10. Species help to distinguish between different types of plants and animals by their difference appearances. Species can be determined by their physical form or structure called morphology, other factors that can determine a species is differentiation in body functions, biochemistry, behavior and ...
Speciation Notes
... Key Idea: BSC depends on reproductive isolation. Problem: How do we classify organisms we cannot observe carrying out sexual reproduction? ...
... Key Idea: BSC depends on reproductive isolation. Problem: How do we classify organisms we cannot observe carrying out sexual reproduction? ...
Hybrid (biology)
In biology a hybrid, also known as cross breed, is the result of mixing, through sexual reproduction, two animals or plants of different breeds, varieties, species or genera. Using genetic terminology, it may be defined as follows. Hybrid generally refers to any offspring resulting from the breeding of two genetically distinct individuals, which usually will result in a high degree of heterozygosity, though hybrid and heterozygous are not, strictly speaking, synonymous. a genetic hybrid carries two different alleles of the same gene a structural hybrid results from the fusion of gametes that have differing structure in at least one chromosome, as a result of structural abnormalities a numerical hybrid results from the fusion of gametes having different haploid numbers of chromosomes a permanent hybrid is a situation where only the heterozygous genotype occurs, because all homozygous combinations are lethal.From a taxonomic perspective, hybrid refers to: Offspring resulting from the interbreeding between two animal species or plant species. See also hybrid speciation. Hybrids between different subspecies within a species (such as between the Bengal tiger and Siberian tiger) are known as intra-specific hybrids. Hybrids between different species within the same genus (such as between lions and tigers) are sometimes known as interspecific hybrids or crosses. Hybrids between different genera (such as between sheep and goats) are known as intergeneric hybrids. Extremely rare interfamilial hybrids have been known to occur (such as the guineafowl hybrids). No interordinal (between different orders) animal hybrids are known. The third type of hybrid consists of crosses between populations, breeds or cultivars within a single species. This meaning is often used in plant and animal breeding, where hybrids are commonly produced and selected, because they have desirable characteristics not found or inconsistently present in the parent individuals or populations.↑ ↑ ↑ ↑