Biology - unit 2 - chapter 4

Micro evolution

Micro evolution

Changes in the frequency of a gene in a population, occurs over a sort period of time with subtle changes, caused by mutations and selection

Microbial evolution

Happens with viruses, bacteria, and single called organisms and the genetically driven changes

Chemical evolution

Assumes all life came from a chemical process of starting with simple chemicals and it evolving for complex molecules eventually creating cells and life, challenge faith

Macroevolutuiton

Large scale changes that result to the evolving of major group into entries new species, monkeys to humans, challenges faith

Coevolution

The joint evolution of two or more systems that interact with each other (predator-prey)

Divergent evolution

Animals of the same species with common ancestors become different over time usually because of geographical barriers (Darwin’s finches)

Convergent evolution

The evolution of two species so they come to closely resemble one another, no the same ancestors

What do marsupials have in common

All have hair, no placenta/umbilical cord, produces milk, and has 3 bones in their ears

Adaptation

A physical feature, behaviour, or physiological process that helps an animal/plant to survive and reproduce in a particular environment

Physical adaptation

Sharp talons, large ears for heat loss, animal color

Behavioural adaptations

Hibernation, mating dance, migration

Physiological adaptations

Inner workings of an organism ex. A plants toxins, blood clotting, changes in cells

Variation

A visible or invisible difference that helps an individual or population to survive, this is passed on by survivor to survivor (eye or fur color)

Natural selection

When variations and the environment in which the population lives causes only the best of the best to live and adapt

Mutations

The change of genetic material (DNA) of an organism which cause variations which can provide advantages disadvantages, or neither, passed on form generation to generation

Disadvantages to mutations

Errors with DNA replication and the physical or chemical agent damages the physical structures of DNA

Advantages of mutations

Organisms become resistant to bacteria (venom, insecticide, antibodies) and being able to protect themselves. Increased likelihood of survival for the species

Scientific theories

Explains facts and lets scientists make prediction about new situation and experimental outcomes

Buffon

Noted similarities between humans and apes and suggested they could be ancestors, thought the world was old

Cuvier

Found organisms in the layer of rock showing older, extinct, species were at the bottom and newer more present fossils were closer to the top an showed the were very different from older fossils, proposed natural events led to extinction

Lyell

Suggested the earth was slowly changing and that it was very old

Lamarck

Pointed out species change over time and get more complex, suggested they changed based on their use or disuse of a function which got passed down (evolution by transformation)

Malthus

Noted populations produce more then can survive to increase the percentage of that spices to survive

Darwin and Wallace

Believed population change over time, the both co-developed the theory of evolution by natural selection, developed the scientific theory

What provides evidence for evolution (7)

Fossil records, biography, anatomy, molecular biology, genetics, and embryology

Fossils and evolution

Fossils show the chronological order of fossils and how they change through the decades. A draw back is things can go missing or not found, also fossils cant tell you everything (colour sound)

Transitional fossils

New discoveries of fossils used to fill gaps in fossil words

Archaeopteryx

Transitional fossils that have characteristics of both dinosaurs and birds

Biogeography

The study of the geographical distribution of organisms (divergent evolution)

What are animals on island most closely related too

Animals on the closest continent

Where are fossils of similar species found

Off the coastline of neighbouring continents

Where are closely related species never found

In the same habitat or location because the niches would have to differ for them to coexist

What are geographically close enviornments more likely to contain

Like organisms or organisms that are related

Homologous structures

Similar structural element and ancestors, different function

Analogous structures

Perform similar functions but have different ancestors ex. Wings on birds

Embryology and evolution

Closely related organisms go through similar stages in their embryonic development

What are 2 things vertebrate embryos have

Paired pouches that turn into ear canals and they have tail bones

Molecular biology

The percentage of our genes we share with other organisms

Genetics an evolution

Scientist now know how species pass on their traits to their offspring and how the blue prints for these traits could change by mutation

Speciation

This happens when a sub species is formed and it develops new characteristics. Can be split into 2 pathways: divergence and transformation. The key is isolation. Long term micro evolution

Transformation

A new species due to accumulated changes in the population over long periods of time. The new species develops mutations and adaptations due to environmental changes and it ends up wiping out the old species

Divergence

Increases biological diversity, one or more species come from one parent which continues to exist

Geographical barriers

Physical abiotic factors that separates populations from interbreeding ex. Mountains, water, lava flow

Biological barriers

Behaviours like bird calls or mating calls/dances, the production of pheromones that prevent populations from interbreeding

What can isolate a species (prevent interbreeding)

Geographical, biological, and reproductive barriers

Reproductive barriers

Genetic variations allows for a species to exploit different resources so the others cannot survive

Adaptive radiation

The diversification of a common ancestral species into a variety of species all of which have differently adapted (Darwin’s finches)

Evolutions gradualism pace

Slow, steady, linear changes over time

Evolutions punctuated equilibrium pace

Long periods of equilibrium interrupted by periods of speciation

The theory of evolution by natural selection

1. All living things are related to each other and have common ancestors. 2.species evolve into other species by acquiring heritable genetic mutations which can result in survival mutations eventually getting passed down to offspring, overall changing the population