Bio chapter 7 (Part one)

Zoonotic

a disease that is transferred from animals to humans

Lamarck

was one of the first to suggest that species change over time, his misconception was that the individuals could change in their lifetime

Lyell

suggested that an old Earth had gradually changed through slow, accumulating processes.

Charles Darwin 

who published On the Origin of Species by Means of Natural Selection.

natural selection & evolution

_____ is the pressure and _____ is the result

Observation: Overproduction (Darwin’s Observations)

More individuals are born than can be supported by the environment.

Observation: Limited resources (Darwin’s Observations)

The amount of resources (such as food, water, shelter, sunlight) stays relatively constant.

Conclusion: Competition (Darwin’s Observations)

More offspring are born than can be supported by limited resources; not all individuals survive and reproduce

Observation: Variation (Darwin’s Observations)

Darwin also observed that no two individuals are alike.

Conclusion: Natural selection (Darwin’s Observations)

Those individuals with variations that make them best suited to their environment will, on average, be more likely to survive and reproduce.

Observation: heritability  (Darwin’s Observations)

The traits of an organism are likely to be passed to the next generation.

Conclusion: Evolution (Darwins Observations)

Because traits are passed from one generation to the next, and because certain members are more likely to survive and reproduce, a population will change over time, becoming better suited to its environment.

Artificial Selection

When humans actively choose and bread individuals of plants or animals with desirable traits to enhance those traits in future generations.

Natural Selection In Action

Antibiotics were first discovered in the 1940s

Today, some antibiotics have become virtually useless because bacteria have evolved resistance

Adaptation

Any sort of characteristic or trait that helps an organism survive and reproduce in its environment.

Camouflage 

Fossils

form when organisms die, fall into accumulating sediment, and are compressed into rock. 

radiometric dating

Fossils can be dated using their geological position or through …

gives an exact date when it happened.

Transitional forms

• provide evidence of change within lineages.

  • whales having knees 

Convergent evolution

is when organisms live in the same environment, they evolve similar traits or characteristics.

Fossilization

It is an unlikely event.

If you went out into your backyard and died, you would probably not turn into a fossil.

Usually occurs in tar pits, sand, mud, amber, or ice.

Biogeography

the study of the geographic distribution of species

For example, the geographic isolation of Australia accounts for the dominance of marsupial mammals.

Comparative Anatomy 

Comparisons of the body structures of modern organisms

Shared embryological stages indicate common ancestry

Bioinformatics

employs computational tools to process genetic data

Populations

is a group of individuals of the same species living in the same place at the same time.

Natural selection acts on individuals.

gene pool

what consists of all versions of all the genes carried by all the individuals in a population

mutation

Genetic variation in a gene pool can arise through this

Sexual reproduction

 ensures that genes are randomly mixed

Microevolution

Traits that enhance survival and reproduction will be represented with increasing frequency in the gene pool

A generation-to-generation change in the gene pool (EVOLUTION ON SMALLEST SCALE)

Darwinian Fitness

Individuals vary in their evolutionary fitness.

is the contribution that an individual makes to the gene pool of the next generation

Fitness depends on the specific environment in which the organism lives.

The strongest individual not always the fittest 

Mutations

Random changes to DNA can create new genes

can happen because of DNA coping mistakes during cell division, exposure to ionizing radiation, exposure to chemicals called mutagens, or infection by viruses.

Bottleneck effect

when a population is drastically reduced in numbers

Founder effect

 if a few individuals migrate to a new isolated habitat

Gene Flow

The genetic exchange among populations due to migration across long distances.

Sexual Selection

A form of natural selection that depends on an individual’s ability to obtain a male.

Females may choose males for their traits

Males may compete with each other for access to mates.

Carbon 14

used to radiometrically date organic materials

Uranium-238

 used to date very old rocks (geologic materials), not organic remains