bio unit 9 (evolution and ecology)

environment

The environment includes everything that surrounds and affects an organism. It includes living things and non-living things.

ecology

Ecology is the study of how living things interact with each other and with their environment.

Interdependence

Interdependence is the idea that organisms rely on one another and on their environment for survival.

Because species are connected through food, shelter, and environmental conditions, a change in one part of an ecosystem can affect many others. For example, animals rely on plants or other animals for food.

examples of ecology in action

lion eating a zebra, plant growing towards the sunlight, recycling

biotic factors

living parts of the environment

ex: plants, animals, fungi, bacteria, archaea

abiotic factors

non-living parts of the environment

ex: sunlight, temp, water, soil, air quality, salinity, pH

what do biotic factors influence

They influence population size, survival, and reproduction through processes such as competition, predation, disease, and symbiosis.

how can an abiotic factor influence a biotic factor

lack of rain or a drought can influence plant growth

what do both abiotic and biotic factors have in common

both work together to shape the environment

both depend upon one another

Ecologically speaking, how is life on Earth organized by scientists?

what do scientists study at different ecological levels of organization?

Life is organized into ecological levels of organization.

Scientists study interactions between individual organism and larger patters, from groups of the same

species to entire ecosystems and the biosphere.

How do ecological levels change as you move upward?

Each level builds on the one before it and becomes more complex.

Species

A group of individuals that can breed to produce

fertile offspring.

population

Includes members of the same species living and interacting in a specific geographic area.

Community

Includes all the different species living and interacting in the same are.

Ecosystem

Includes all the biotic and abiotic factors in an area working together.

Biome

A large geographic region defined by its climate, soil, and plant and animal communities.

Biosphere

Includes all biomes, ecosystems, and living things on Earth

energy

the power needed to do work, such as staying alive

food chains and energy basic stuff

most living things are in multiple food chains

all energy starts with the sun

plants use caron dioxide water and sunlight to produce sugar and o2

energy is not converted into chemical energy by animals

energy from grass is transferred to a rabbit that eats it

every living thing needs matter and energy to survive

without the sun’s energy there would be no life on earth

most food chains have three to five links (10% rule)

Food chain

A model that shows how energy flows between living things.

system

A self-contained collection of different things that work together as a whole.

ecosystem

A system of living things and their environment.

the 10% rule

Approximately 10% of the energy consumed by an organism passes on to the next link in the food chain.

Only 10% of energy moves from one trophic level to the next.

Most energy is lost as heat or metabolic and digestive waste as an organism lives its life.

food chain order

producer, primary consumer, secondary consumer, tertiary consumer, top predator

herbivore, carnivore, omnivore, decomposers

you know this

decomposer eat decaying matter and decompose

Decomposers don’t just put energy back into the food chain ecosystem, they also keep waste from piling up in an ecosystem.

what four things to animals need to live

food, water, shelter, space

food web

Big, tangled systems that include every plant and animal in a habitat.

what are phytoplankton and who eats them

tiny plants

zooplankton

what would happen if we remove an organism from a food web

Removing just one organism from a food web is potentially devastating to an ecosystem. This is because organisms in a food web are interconnected and rely on one another for survival. If one organism is removed, all other organisms become threatened.

detritus

why would so many arrows point back to it?

Organic matter produced by the decomposition of organisms. Base of brown food chain.

Because everything eventually dies. Whenever the dead organism (or parts of it) decays, it turns into detritus.

autotroph

A plant, a producer, an organism that makes its own food.

heterotroph

Consumers, they need to feed on other organisms.

biodiversity

the variety of all types of organisms living in a given area

Biodiversity can contribute to the sustainability of an ecosystem.

What is a trophic level?

The feeding position in a food chain or food web. Or energy pyramid.

natural selection

the primary mechanism of evolution. It is the process where organisms better adapted to their environment are more likely to survive, reproduce, and pass on their beneficial traits, causing the species to change and adapt over successive generations

comparative anatomy

Scientists study comparative anatomy to understand how organisms

are related and how species have changed over time. By comparing

body structures in different organisms, scientists look for patterns that

provide evidence for evolution.

homologous structures

body parts with similar internal structures

can be used for different purposes

suggests that the organisms share a common ancestor

analogous structures

perform similar functions but have different internal structures

not come from a recent common ancestor

how how differnt species can adapt in similar ways to similar environments

vestigial structures

structures that are reduced or no longer useful

functional for ancestors but have changed overtime has the environment and lifestyles changed

adaptation

When a trait increases an organism’s ability to survive and reproduce in a specific environment

biological fitness

refers to how successful an organism is at surviving and reproducing in its environment.

Birds that are better able to collect food have more energy to survive and produce offspring. Because of this, birds with beak shapes that function well in a particular environment have higher fitness, and their beak shape is considered an adaptation.

leads to natural selection

study of embryos

embryology

When scientists compare embryos from different species, they are using comparative embryology.

molecular biology

The study of DNA and other molecules inside cells is called molecular biology.

Scientists use molecular biology to understand how organisms function and how they are related to one another.

Scientists use molecular biology to compare DNA sequences and look for patterns of similarity. By counting how many DNA bases match between organisms, scientists can determine how closely related they are. This type of molecular evidence is especially powerful because it is precise and supports other evidence of evolution, such as fossils, comparative anatomy, and embryology.

divergent evolution

when closely related species become more different over time

share a common ancestor but they adapt to different environments or ways of life

example: the forelimbs of humans, bats, and whales all have the same basic bone structure, but they are used for different functions like grabbing, flying, and swimming.

convergent evolution

when unrelated species develop similar traits. These similarities form because the species live in similar environments or face similar challenges, not because they share a recent common ancestor.

ex: sharks and dolphin bodies

Adaptive radiation

a pattern where one ancestral species rapidly evolves into many different species. Each new species becomes adapted to a different environment or resource.

ex: Galápagos finches, which evolved different beak shapes to feed on different types of food on the islands.

coevolution

when two or more species influence each other’s evolution. As one species changes, the other species also changes in response.

ex: flowering plants and their pollinators often evolve together, with flower shapes and pollinator body parts becoming more specialized over time.

genetic drift

allele frequencies change by chance, not because one allele is better than another.

Genetic drift often occurs in small populations or after random events like storms or disease. When individuals are randomly removed from a population, some alleles may become more common while others may become rare or disappear entirely, simply due to chance.

gene flow

Gene flow happens when

individuals move from one population to another and reproduce. When this occurs, new alleles can be added to a population, or the proportion of existing alleles can change. Both genetic drift and gene flow can cause evolution even when no adaptation is occurring.

speciation

is the process by which one species splits into two or more new species.

This happens when populations become reproductively isolated, meaning they can no longer successfully mate and produce offspring.

When reproductive isolation occurs, gene flow between populations is reduced or stopped, allowing the populations to change independently over many generations.

common ways reproductive isolation can occur

Geographic isolation: Populations are separated by a physical barrier, such as a river, mountain, or canyon, preventing them from mating.

Temporal isolation: Populations reproduce at different times, such as different seasons or times of day.

Behavioral isolation: Differences in mating behaviors, such as courtship dances or mating calls, prevent mating.

Mechanical isolation: Physical differences in body structures prevent successful mating.

parasitism

one species (the parasite) benefits at the expense of the other which is harmed

mutualism

both species benefit from the interaction

ex: bees and flowering plants

commensalism

one benefits, while the other is neither helped nor significantly harmed

ex: barnacles on whales

predation

one organism hunts kills and consumes another organism for food

ex: lions and zebras

competition

both species negatively impacted as they go for the same resources

ex: lions and hyenas