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Flashcards in Final Exam: Cumulative Stuff Deck (21):
1

What is natural selection?

Forces of nature that pick winners and losers in one specific generation, with winners earning the ability to propagate further. Evolutionary arms race

2

Define natural selection

A mechanism that can lead to evolution, whereby differential survival or reproduction of individuals causes some genetic types to replace (outcompete) others

3

5 Facts of Natural Selection

1. All species have such great potential fertility that their population size would increase exponentially if all individuals born reproduced successfully.
2. Except from minor annual fluctuations and occassional major fluctuations, populations normally display stability
3. Natural resources are limited. In a stable environment they remain relatively constant.
4. No 2 individuals are exactly the same; every population displays enormous variability
5. Much of this variation is heritable.

4

3 Inferences of Natural Selection

1. There must be a fierce struggle for existence among the individuals of a population, resulting in the survival of only a part of the progeny in each generation.
2. Survival is not random but depends on hereditary constitution of surviving individuals
3. This process of NS will lead to a continuing change of populations - to evolution and production of new species

5

Dorudon

A 40-million year old whale, has teeth of different shapes that indicate that they were more of those of land mammals

6

NS: More _____ are produced in a population than can survive

Offspring

7

NS: As a result of mutations creating new alleles and segregation and independent assortment shuffling alleles into new combinations, individuals within populations are _____ for many traits.

Variable

8

Individuals pass their alleles onto their offspring _____

Intact

9

In every generation, some individuals are more successful at _____ and _____ than others.

Surviving and reproducing

10

Individuals that survive and reproduce or who reproduce the most, are those with the _____ and _____ that best adapt them to their environment

Alleles and allelic combinations

11

Natural selection acts on _____, but its consequences occurs in _____. _____ do not evolve

Individuals; populations
Individuals

12

NS acts on _____, but evolution consists of changes in _____.

Phenotypes
Allele frequency (genotype)

13

NS is not _____ _____.

Forward looking

14

New traits can evolve, even though NS acts on _____

Existing traits

15

NS does not lead to _____

Perfections

16

NS is _____, but it is also not _____.

Nonrandom or progressive

17

Selections acts on _____, not for the good of the species.

Individuals

18

NS: _____ in characteristics occurs in the population.

Variation

19

NS: _____ in biological fitness occurs in the population

Variation

20

NS: Individuals in the population _____ for resources

Compete (competition drives)

21

_____ influence which individuals with a given genetic phenotype will best survive and compete, thus will leave the most offspring in the next generation.

Prevailing environmental conditions