Biology Test 2

Ecology

Concerned with explaining the distribution and abundance of organisms around the world.

Species distribution

Different floras and faunas are the result of the independent evolution of separate, unconnected populations which have generate different places.

Jean-Baptise Lamarack

Who first formulized and published theory of evolution called “transformation”? (Use or disuse determined whether traits were passed on.)

Drive for complexity

The idea that living things evolved toward ever more complex forms, ending in human “perfection”.

Charles Darwin

Who proposed the theory of evolution by natural selection?

Malthusian Theory of Population

Malthus proposed that because the Earth was not overrun by humans, food shortage, disease, war, or conscious control must limit population growth.

Theory of natural selection

A better-adapted organism would acquire more resources and leave more offspring.

adaptation

Over long periods of time, natural selection leads to..?

Allele frequency

# of copies of a specific allele in a population / total # of all alleles for that gene in a population

Genotype frequency

# of individuals with a particular genotype in a population / total # of individuals in a population

Hardy-Weinberg equation

Predicts unchanging allele and genotype frequencies in a population, a situation referred to as equilibrium.

equilibrium

When at __________, a population is not adapting and evolution is not occurring.

Population

A localized group of individuals capable of interbreeding and producing fertile offspring.

Gene pool

All the alleles for all loci in a population.

fixed

An allele for a particular locus is _____ if all individuals in a population are homozygous for the same allele.

one

The frequency of all alleles in a population will add up to..?

Genotype

_________ frequencies are represented by: p² + 2pq + q² =1

allele

The equation for ______ frequency is p + q =1

expected

Population is only in equilibrium if the __________ frequencies are the same as the actual frequencies.

hypothetical

The Hardy-Weinberg theorem describes a __________ population that is not evolving.

No genetic drift, migration/gene flow, natural selection, mutations, and assortive mating

What are the conditions for the Hardy-Weinberg Principle?

Microevolution

A change in allele frequencies in a population over generations.

Natural selection, genetic drift, gene flow, and mutation

What four mechanisms cause allele frequency?

natural selection

Only _________ __________ causes adaptive evolution.

mutation

Only ______ creates brand new alleles.

small

When population sizes become too _______, individuals accumulate deleterious mutations and are more likely to suffer genetically from random events.

Inbreeding

__________ is more likely to take place in nature when population size is small and the number of mates is limited.

50

A population of at least __ individuals is necessary to prevent the deleterious effects of inbreeding for the immediate future.

extinction vortex

Downward spiral toward extinction.

500

A population size of at least ___ is necessary to decrease the effects of genetic drift.

effective

In many populations, the _________ population size, which is the number of individuals that contribute genes to future populations, may be smaller than the actual number of individuals in the population.

against

Alleles that are maladaptive are selected ________.

genetic drift

Describes how allele frequencies fluctuate unpredictably from one generation to the next.

Founder effect

Occurs when a few individuals become isolated from a larger population.

phenotype, genotype

Natural selection cares about _________, not _________.

relative fitness

The contribution an individual makes to the gene pool of the next generation, relative to the contributions of other individuals.

Natural selection

______ ________ indirectly favors certain genotypes by acting directly on phenotypes.

Phenotype

The product of inherited genotype and environmental influences.

Migration

_________ consists of the movement of alleles among populations.

reduce

Gene flow tends to ________ genetic variation among populations over time.

mutations

Mistakes that get past the checkpoits.

Biological distinction

Species are separate if they are unable to interbreed and produce fertile offspring.

Morphological distinction

Differences in physical characteristics or molecular characteristics are used to distinguish species.

Evolutionary distinction

Phylogenetic trees and analyses of ancestry to serve to differentiate species.

Ecological distinction

Species separate based on their use of different ecological niches and their presence in different habitats and environments.

mutation

A change in the nucleotide sequence of DNA.

offspring

Only mutations in cells that produce gametes can be passed to ________.

Point mutation

A change in one base in a gene.

short

______ generation times allow mutations to accumulate rapidly in prokaryotes and viruses.

hybrids

In plants, ________ often form when parents from two different species are crossed with each other, and sometimes their offspring can be fertile. This greatly blurs species distinctions.

asexually

The biological species concept cannot be applied to ________ reproducing species such as bacteria and some plants and fungi.

niche

Each species occupies a distinct ecological ________.

niche

A unique set of habitat requirements.

hybridization

Introduced species can bring about a form of extinction via ____________.

Populations

Groups of interbreeding organisms.

Abundance

The total number of individuals in the population.

Density

Number of individuals per unit area.

mix

After the tagged animals are released within the mark-recapture technique, they ___ freely with unmarked individuals and withing a short time are randomly mixed within the populations.