Biology Evolution, Ecology, and Environmental Science Review

Natural Selection

- organisms with helpful traits survive and reproduce

Describe adaptation.

inherited helpful trait that helps organisms

Directional selection -

Traits favored by environment

Diversifying selection -

Both extreme traits are favored

stabilizing selection

middle/ average trait is faired yet less successful

Describe antibiotic resistance.

- Bacteria surviving antibiotics due to overuse or misuse

Bacterial Fitness -

How well a bacteria variant can survive and reproduce

- Antibiotic- sensitive Variant:

Low fitness

- Antibiotic- resistant variant:

medium fitness

-Highly antibiotic- resistance:

High fitness

Reproduction -

allows organisms make off springs

Non-adaptive evolution

- Changes in a population that happens without making the population better adapted.

Speciation -

Forming of a new species.

Gene pool -

all allies present in a population

Genetic variation -

Differences in gene and traits among individuals in a population

Genetic drift -

Random change in an allele frequency

Gene flow -

movement of alleles between populations

Evidence for evolution

1. Fossil Record

2. Comparative anatomy

3. Comparative biochemistry

4. Comparative embryology

5. Molecular biology

6. Biogeography

-Fossils:

Organisms that live in the past and how life has changed over time.

- Comparative anatomy:

Comparing body structures with other organisms.

-Embryology:

Comparing early development with different organisms.

Biogeography

studying where organisms live and how it relates to evolution.

Fossil record

all fossils discovered and studied by scientists.

Taxonomy

classifying organisms groups based on shared characteristics, genetic similarities, evolution and classification order.

- Domain-> kingdom ->phylum-> class -> order ->family -> Genus -> Species

Taxonomy

Human evolution

Homosapiens, we have the same DNA as chimpanzees and we might have originated in Africa before moving away

mtDNA inheritance -

Is passed from mom and her kids not inherited in sperm and can be traced though many generations

Mitochondrial Eve

- Her DNA is shared by all humans

Melanin and skin color

- Melanin: pigment of skin color produced by melanocytes

UV light -

Higher UV means more melanin and darker skin while low UV means less melanin and lighter skin

Folate -

Important for cell division and development good for sperm production + brain & spinal development before birth

Vitamin D

Healthy bones, teeth and immunity.

Population ecology

- study of how population changes over time

Community ecology -

different populations living in the same area

Ecosystems -

living and non living organisms in the same area living and non living organisms in the same area

- Exponential growth:

Population increases very rapidly when resources are plentiful. J curve

- Logistic growth:

population grows quickly at first then slows as resources become limited. S shaped

Density - dependent factor:

Factors that have a greater effect when a population becomes crowded.

Density- independent factor:

factors that affect a population regardless of population size or crowding.

Biotic factors -

Living parts in an environment

Abiotic factors -

non living parts of an environment

Food chains -

simple pathways that shows how energy moves to organism

Food webs -

shows several connected food chains

Trophic levels -

An organism's feeding positions in a food chain.

Carbon cycle -

continuous movement of carbon between the atmosphere, living organisms, oceans and earth

Global climate change -

Long-term changes in Earth's temperature and weather conditions.

Greenhouse gases and their effects -

natural process in which gases in Earth's atmosphere traps some heat, helping maintain Earth's surface temperature.

Renewable resources -

Natural resources that can be replaced in a short time

Non-renewable resources

Natural resources that are limited

Sustainable living -

choices that reduce harm to the environment and conserves natural resources.