Evolution

evolution

changes in the heritable traits of a biological population over generational time

Genotype

information stored in DNA

Gene

a segment of DNA that contains the instructions for building a specific protein or performing a particular function

Phenotype

all structures, processes, and behaviors of an organism; specific

Trait

facet of the phenotype; general characteristics

Heritable Trait

a trait encoded by genes that is inherited across generations

What is the major unifying principle of biology?

evolution

Population

a group of organisms from the same species, existing at the same time in the same space

Choose the correct answer.

Evolution acts on populations, individual organisms do not evolve.

Generation

organisms within a population that consists of a single step in the line of descent from an ancestral cohort

Why does evolution happen overtime?

it takes time for changes generate and accumulate within a population

What are the five mechanisms of evolution?

altered DNA sequence, gene flow, genetic drift, natural selection, sexual selection

Altered DNA sequence

only source of new genes; random change in the sequence of an organism’s DNA; only sometimes affects phenotypes

Gene Flow

migration of random individuals (and their genes) between populations

Genetic Drift

random changes in the gene pool of a population; ex: bottleneck

bottleneck

changes in variation in a small population; ex: hunting

What can randomly change number of variations of a gene in the population?

gene flow and genetic drift

Natural Selection

differential survival of individuals with certain traits but not others

Sexual Selection

differential reproductive success of individuals with certain traits but not others

True or False: Evolution has no goal or conscious intention.

True

In sexual selection, the trait in question…

has to be passed to offspring (inheritable)

When a population decreases in numbers greatly because of hunting and habitat destruction, what is the mechanism of evolution or no evolution involved?

genetic drift

A study is conducted to see if longer tails on birds has any impact on reproductive success. The birds with longer tails attracted more females than those with clipped tails. What is the mechanism of evolution or no evolution involved?

sexual selection

An experiment clipped tails of some moths and not others. Moths with tail wings were eaten significantly less than those with clipped wings but the ability to fly was not affected. What is the mechanism of evolution or no evolution involved?

natural selection

There are 3 species of Monkey Flower. One is found in mid-to-high elevation and pollinated by bees and another is found in low-to-mid elevation and pollinated by hummingbirds. A hybrid population is formed in the range overlap and is pollinated by both. What is the mechanism of evolution or no evolution involved?

gene flow

Birds are fitted with leg bands. Females are more attracted to the birds with red plastic leg bands than un-banded males and avoid males with blue or green bands. What is the mechanism of evolution or no evolution involved?

not evolution

What limits Evolution?

all of the above