Microevolution

What is macroevolution?

its a large-scale evolutionary changes that take place over long periods of time.

What is speciation?

its the process by which one species splits into two or more species.

What is divergent evolution?

its when Related species evolve difference due to adaptation to different environments.

What is convergent evolution?

its when Unrelated species evolve similar traits independently.

What is natural selection?

The process by which traits that enhance survival and reproduction become more common in a population.

What does natural selection enhance?

Survival and reproduction.

What is artificial selection?

Its when Humans selectively breed organisms for desired traits.

What is Sexual selection?

its a type of natural selection where traits that increase mating and becomes more common.

What is genetic drift?

its Random changes in allele frequencies, especially in small populations.

What is Adaptive Radiation?

Its when rapid diversification of a single ancestral speices goes into multiple new species and often in response to a new ecological opportunities.

Whats Mass Extinction?

its a large-scale extinction events that wipe out a significant proportion of life. an example can be when dinosaurs got hit with the meteor.

Whats the difference between Homologous and Analogous?

Homologous trait- is traits that have a common evolutionary origin but different functions (forelimbs of humans, bats, and whales)

Analogous trait- is traits with similar functions but different evolutionary origins (wings in birds and insects)

whats is Stabilizing, Directional. and Disruptive Selection?

-Stabilizing selection- is when one favors intermediate phenotypes (human birth weight)

- Directional selection- is when favors one extreme phenotype (larger beaks in finches during a drought)

- Disruptive Selection- Favors both extreme phenotypes (large and small beaks in finches)

What is Reproductive isolation?

Pre-zygotic barriers- prevent fertilization (habitat isolation, behavioral isolation)

Post-zygotic Barrier- Reduce fitness of hybrids

Whats the difference between Convergent and Divergent Evolution?

Convergent- unrelated species evolve similar traits (wings in bats and birds)

Divergent- related species evolve different traits (Darwin Finches)

What is a homologous chromosome?

one of two paired chromosomes, one from each parent, that carries genes for a specific trait at the same location

What is homozygous?

its the same allele for a gene is present on both homologous chromosome.

What is heterozygous?

its different allele for a gene are present in a homologous chromosome.

What are genes?

segments of DNA that codes for a protein.

What are alleles?

they are different version of a gene.

What is a genotype?

The genetic makeup of an organism for a particular gene (e.g. RR).

What is a phenotype?

traits that are observable characteristic of an organism

What is a dominant allele?

A form of a gene that is fully expressed, even when two different alleles are present

What is a recessive allele?

will only be expressed and affect phenotype when in the homozygous genotype condition.

What is polygenic?

controlled by many genes

What is Gene flow?

the transfer of alleles or genes from one population to another

What is genetic drift?

random change in allele frequency in a population

What is a mutation?

change in DNA sequence

what is natural selection?

The idea that the fittest survive and pass along their traits to their offspring.