APES: QA6 - Evolution and Biodiversity

Adaptation

Adaptive trait with functional role in organisms evolved by means of natural selection

Microevolution

Evolutionary change within a species or small group of organisms, especially over a small period of time

Genotype

Genetic constitution that determines phenotype;

Gene

Unit of heredity passed down from parent

Geographic Isolation

Allopatric speciation, also referred to as _____________, vicariant speciation, or its earlier name, the dumbbell model, is a mode of speciation that occurs when biological populations of the same species become isolated from each other to an extent that prevents or interferes with genetic interchange. Various geographic changes can arise such as the movement of continents, and the formation of mountains, islands, bodies of water, or glaciers. Human activity such as agriculture or developments can also change the distribution of species populations.

Genetic Mutation

In biology, a mutation is the permanent alteration of the nucleotide sequence of the genome of an organism, virus, or extrachromosomal DNA or other genetic elements.

Adaptive radiation

drives divergent evolution; evolve from ancestor and fill different niches

Genetic Diversity

the total number of genetic characteristics of a given species, subspecies, or group of species (or genes); becoming more difficult to measure

There are more than 600 species of trees in Costa Rica, most of which are in the rainforests. What might account for the coexistence of so many species with similar resource needs?

An abundance of resources and various costal and mountainous regions can house wide range of tree species.

Life on Earth has changed significantly in the 3.5 billion years since life first evolved. What do scientists think caused the several major extinctions that have occurred on Earth?

Asteroid impacts, climate change, volcanoes

Example of realized niche

Before European settlers came to North America, wolves ranged across the continent. Larger and stronger than coyotes, they were able to compete well for food and territory. The coyotes had a difficult time competing for the same habitat. Coyotes, therefore, had a limited realized niche.

Genetic drift: Give 2 reasons why genetic drift is a problem in very small populations (including endangered species).

Every population experiences genetic drift, but small populations feel its effects more strongly. Genetic drift does not take into account an allele's adaptive value to a population, and it may result in loss of a beneficial allele or fixation (rise to 100% percent frequency) of a harmful allele in a population.

Biological diversity is one of the most important indicators of the health of an ecosystem. List and describe at least: 5 factors that tend to decrease biological diversity.

Factors that tend to decrease biodiversity are extreme environmental conditions, large environmental disturbance, intense environmental stress, severe shortages of key resources, nonnative species introduction, and geographic isolation. ex.) humans logging for lumber to make room for agriculture, housing, and industry destroys forest ecosystems and the diverse species they house.

Biological diversity is one of the most important indicators of the health of an ecosystem. List and describe at least: 5 environmental factors that tend to increase biological diversity

Factors that tend to increase biodiversity are the middle stages of succession, moderate environmental disturbance, small changes in environmental conditions, physically diverse habitat, and evolution. ex.) As climate changes, populations will undergo speciation, resulting in the formation of greater biodiversity.

Which of the following can lead to populations that are less adapted to the environment than their ancestors (and explain how that could happen for each): a. Natural selection b. Migration c. Mutation d. Genetic drift

Genetic drift (possibly less biodiversity), mutation, migration

Example of competitive exclusion principle

In competitive exclusion, one species is displaced by another when their niches overlap and they compete for the same resources. The 'winning' species out-competes the 'losing' species. This can occur during environmental change, when a new species enters an ecosystem and its presence conflicts with native species. Because of competitive exclusion, and other ecological factors, species do not always fill the full niche that they have the potential of filling. This is called the fundamental niche. Instead, they end up occupying a portion of the fundamental niche. This is called their realized niche.

Gene Flow

In population genetics, ________ is the transfer of genetic variation from one population to another. If the rate of gene flow is high enough, then two populations are considered to have equivalent genetic diversity and therefore effectively a single population. It has been shown that it takes only"One migrant per generation" to prevent population diverging due to drift.

Macroevolution

Major evolutionary change; usually applies to large taxonomic groups over long periods of time.

Natural Selection

Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, the change in heritable traits of a population over time. Charles Darwin popularised the term"natural selection", and compared it with artificial selection; POPULATIONS evolve--NOT individuals

Reproductive isolation

Occurs when members of different populations can no longer mate successfully with one another

Which planet has more biodiversity: one w/ tectonic shifts or one without?

One with tectonic shifting because there would be more niches and in turn more biodiversity.

Genetically Modified Organisms

Organisms in which its genetic material has been changed and does not change naturally

Phenotype

Physical expression of gene/genotype; observable characteristics result of gene interaction with environment

Species Evenness

Species evenness refers to how close in numbers each species in an environment is. Mathematically it is defined as a diversity index, a measure of biodiversity which quantifies how equal the community is numerically. So if there are 40 foxes, and 1000 dogs, the community is not very even.

Species Richness

Species richness is the number of different species represented in an ecological community, landscape or region. Species richness is simply a count of species, and it does not take into account the abundances of the species or their relative abundance distributions.

Gene Pool

Stock of genes in an interbreeding population

Fitness

The biological concept of _____ is defined as reproductive success.

Biological Evolution

The change in inherited characteristics of a population over successive generations; Evolutionary processes give rise to biodiversity at every level of biological organisation, including the levels of species, individual organisms, and molecules. Repeated formation of new species, change within species, and loss of species throughout the evolutionary history of life on Earth are demonstrated by shared sets of morphological and biochemical traits, including shared DNA sequences.

You are going to conduct a survey of biodiversity in national parks. What relationship would you expect to find between the number of species of trees and the size of the parks?

The larger park likely will have more geographic diversity and there will be more species of trees.

Range of tolerance

The limits to the abiotic conditions that a species can tolerate; The ability to survive and reproduce under a range of environmental circumstances

Example of fundamental niche

The male red-winged blackbird's mating call can be heard in the marshes in early spring. At that time, they hold the prime real estate in the marsh. However, as the season progresses, the more aggressive tri-color blackbirds move in. The tri-colors take over the best territory and force the red-wings to choose the leftovers. The entire marsh represents the red-winged blackbirds' fundamental niche.

Competitive exclusion principle (pg. 205-6)

The principle stating that two species competing for the same limiting resource cannot coexist

Realized niche

The range of abiotic and biotic conditions under which a species actually lives

Fundamental niche

The suite of ideal abiotic conditions under which a species can survive, grow, and reproduce

Niche generalists

a species that can live under a wide range of abiotic or biotic conditions

Allopatric speciation

also referred to as geographic speciation, a mode of speciation that occurs when biological populations of the same species become isolated from each other to an extent that prevents or interferes with genetic interchange. Various geographic changes can arise such as the movement of continents, and the formation of mountains, islands, bodies of water, or glaciers. Human activity such as agriculture or developments can also change the distribution of species populations

Extinction

end of an organism or of a group of organisms, normally a species

Evidence for Evolution

fossil evidence shows how animals have changed over time on earth; homologous structure show similarities between fossils and bones in organisms suggesting common ancestor; analogous structures develop differently but have similar functions; different embryos look extremely similar; protein/amino similarities; appendix

Species Diversity

is quite important

Migration

is the movement from one place to another with the intentions of settling, permanently or temporarily in a new location

Founder effect

loss of genetic variation that occurs when a new population is established by a very small number of individuals from a larger population; genetic makeup changes from original population --> chance occurrence

Sympatric speciation

new species evolve from a single ancestral species while inhabiting the same geographic region; sympatric and sympatry are terms referring to organisms whose ranges overlap or are even identical, so that they occur together at least in some places

Bottleneck effect

sharp reduction in the size of a population due to environmental events or human activities. Such events can reduce the variation in the gene pool of a population; thereafter, a smaller population, with a correspondingly smaller genetic diversity, remains to pass on genes to future generations of offspring through sexual reproduction. Genetic diversity remains lower, increasing only when gene flow with another population occurs or very slowly increasing with time as random mutations occur.

Ecosystem Diversity

the different types of habitat/ecosystem in given area

Genetic Drift

variation in the relative gene frequency of different genotypes in a small population; some genes will disappear if organisms die/fail to reproduce

Niche specialists

would be most vulnerable to environmental changes; specialized to live in a specific habitat or feed on a small group of species.