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form of reproductive isolation in which two populations are separated by geographic barriers such as rivers, mountains, or bodies of water, leading to the formation of two separate subspecies
form of natural selection in which individuals at one end of a distribution curve has higher fitness than individuals in the middle or at the other end of the curve
from of reproductive isolation in which two populations develop differences in courtship rituals or other behavior that prevent them from breeding
selective breeding of plants and animals to promote the occurrence of desirable traits in offspring
heritable characteristic that increases an organism's ability to survive and reproduce in an environment
change in allele frequencies as a result of the migration of small subgroup of a population
a change in allele frequency following a dramatic reduction in the size of a population
Hardy Weinberg Principle
principle that states that allele frequencies in a population remain constant unless one or more factors cause those frequencies to change
form of natural selection in which individuals near the center of the distribution curve have higher fitness than individuals at either end of the curve
separation of a species or population so that they no longer interbreed and evolve into two separate species
process by which organisms that are most suited to their environment survive and reproduce most successfully, also called survival of the fittest
all the genes, including all the different alleles for each gene, that are present in a population at any one time
form of reproductive isolation in which two or more species reproduces at different times
random change in allele frequency caused by a series of chance occurrences that cause an allele to become more of less common in a population
number of times that an allele occurs in a gene pool compared with the number of alleles in that pool for the same gene
structure that is inherited from ancestors but has lost or all of its original function
form of natural selection in which individuals at the upper and lower ends of the curve have higher fitness than individuals in the middle or at the other end of the curve.
method used by researchers that uses mutation rates in DNA to estimate the length of time that two species have been evolving independently
comparison of DNA sequences between species can show how many mutations occurred independently in each group
3 distinctive patterns of biological diversity
1. species vary globally
2. species vary locally
3. species vary over time
Hutton and Lyell
geologists. said that Earth is older than we previously thought. said that processes that changed Earth in the past are the same processes we see in the present
had a false statement that organisms can pass acquired characteristics to their offspring. was first to suggest a link between an organism's environment and its body structure
scientist that stated that if populations grew unchecked, there wouldn't be enough living space and food for everyone
Alfred Russel Wallace
spent year observing and gathering data in Indonesia area and wrote a letter to Darwin. discovered "reproductive isolation" in the Malay Archipelago
descent with modification
living species are descended, with modification, from common ancestors.
according to this all species - living and extinct- are descended from ancient common ancestors
natural selection on single- gene traits
can lead to changes in allele frequencies which changes frequencies of phenotypes
natural selection on polygenic traits
can affect the distribution of phenotypes in 3 ways:
directional, stabilizing, disruptive
any genetically controlled trait that increases an individual's ability to pass along its alleles
sources of genetic variations
muatations, genetic recombination in sexual reproduction, lateral gene transfer
evolution in genetic terms
any change in the relative frequency of alleles in the gene pool of a population over time
The Grants' Investigation
documented that natural selection takes place frequently and sometimes rapidly.
showed that variation within a species increases the likelihood that the species can adapt and survive environmental change
5 conditions to maintain genetic equilibrium
must be random mating
population must be very large
no immigration or emigration
no natural selection
determine which part of an embryo develops arms, legs, or wings. Groups of hox genes also control the size and shape of the those structures
small changes in this can cause activity during embryological development to produce large changes in adult animals
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