Evolution Themed Notes

Abiogenesis, or origin of life, is the study of how life on Earth emerged from inanimate organic and inorganic molecules.

Biogenesis is the process of lifeforms producing other lifeforms.

Similar embryos- common ancestor

Homologous structures- similar structures

Competition has to exist for evolution to occur

To survive a species needs to fill niches and decrease competition

Evolution- Tree of life

Sympatric- Speciation within a population

Allopatric- Isolated population's speciation

Parapatric- Speciation two populations barely overlap 

Allopatric is the fastest while sympatric is the slowest form of evolution

Stabilizing selection- culls extreme variants from the population

Directional selection- shifts the overall makeup of a population

Diversifying selection- favors variants of opposite extremes over intermediate individuals

Gradual change- Even change over life, not many changes, and little evolution occurs

Divergent Evolution- Started the same, but is experiencing a different environment and different pressures

Adaptive Radiation or niche- Different ways of life (Founder effect), needed to survive

Convergent evolution- Coming together from a common ancestor

Finally Gradualism- gradual change

Punctuated Equilibrium- rapid change causes change in organisms immediately

Bottleneck effect- diversity->event->a few surviving population

Kingdom Video

The Classification System

The Classification System

Taxonomists group living things into a hierarchy that moves from general to specific. Organisms found in the same Kingdom are related, but not closely related. Presently, scientists accept that there are five Kingdoms of living organisms: Animalia, Plantae, Protoctista, Fungi, and Monera. The Animalia, Plantae, Fungi and Protoctista are part of the Domain Eukarya. The Kingdom Monera contains two Domains: the Eubacteria and Archea. Currently, there is some of debate among scientists with respect to the Kingdom level of classification because the use of DNA-based technology has allowed us to look more closely at the genetic relationships between organisms.

Each Kingdom is divided into smaller groups called Phyla (singular Phylum) that contain more closely related organisms. Each Phylum, in turn, is subdivided into smaller groups called Classes. A Class is composed of many Orders, which contain a number of Families. A Family of living things is made up of Genera (singular Genus). Finally, each Genus is divided into the smallest and most closely related group of organisms called the species.

The smallest grouping in the taxonomy hierarchy is the species, which contains organisms that are very closely related. In order to be classified in the same species, the organisms must be able to produce viable (fertile) offspring. The species level is the most reliable and useful to scientists.

The following diagram illustrates the taxonomic relationships accepted by many scientists today:

Classification

Classification 

As a result of the confusion using common names, scientists have designed a system to classify or group living organisms. Today, the modern science of grouping living things is called Taxonomy. Taxonomists put all living things into arbitrarily selected groupings or categories that lump the organisms together with other living things based on:

• Structural similarities and differences
• Genetic similarities and differences
• Biochemical similarities and differences
• Cellular organization
• Evidence from evolutionary relationships

Hardy-Weinberg

The Hardy-Weinberg Theorem states that the allele frequencies of a gene in a population will remain constant, as long as evolutionary forces are not acting. H-W therefore provides a baseline (a null expectation) for a population that is not evolving. For a population to be in H-W equilibrium, the following conditions or assumptions must be met:

1. The population is very large; there is no genetic drift
2. Matings are random
3. There is no mutation
4. There is no migration
5. There is no selection

If one of these conditions is broken, an evolutionary force is acting to change allele frequencies, and the population may not be in H-W equilibrium. Natural populations probably seldom meet all of these conditions; H-W provides a nice model to study evolution via deviations from H-W equilibrium.

Hardy Weinberg Equation

Basic Relations

A = dominant allele
a = recessive allele

p + q = 1
Where p = frequency of A allele
q = frequency of a allele

p2 + 2pq + q2 = 1
Where p2 = frequency of AA genotype
2pq = frequency of Aa genotype
q2 = frequency of aa genotype

Week of 11/3-7

Monday- Continued from last week

Tuesday-Also continued from last week by playing Biology themed trouble.

Wednesday- Continued from Tuesday

Thursday- Today we were supposed to have a Test: Evolution and Taxonomy but it was delayed because we were behind. Instead we had lecture today.

Friday: Today we assessed, described and explained adaptations affecting survival and reproductive success, such as: Structural adaptations in plants and animals (form to function), disease-causing viruses and microorganisms, and co-evolution.

Main ideas today included:

• Feeding adaptations.
• Adaptations to ensure successful reproduction.
• Adaptations to life on land.
• Structure of viruses.
  
• Mutation of viruses and other microorganisms.
  
• Variety of disease causing (pathogenic) agents (viruses, bacteria) including: 
  
• HIV
  
• Influenza
  
• Smallpox
  
• Streptococcus (strep throat)
  

Week of 10/27-31

Monday- Today we learned how to use dichotomous keys to identify and classify organisms.

Tuesday- We discussed similarities and differences between eukaryotic and prokaryotic organisms, and similarities and differences among the eukaryotic kingdoms: Protists, Fungi, Plants, and Animals.

A few notes include:

• Membrane bound organelles - none in prokaryotes.
• Ribosomes in both.
• Contrasts in chromosome structure.
• Contrasts in size.
• Cellular structures.
• Unicellular vs. Multicellular.
• Methods of making/getting food and breaking down food to get energy.
• Reproduction.

Wednesday- Today we analyzed the process by which organisms representative of the following groups accomplish essential life functions including: Unicellular protists, annelid worms, insects, amphibians, mammals, non-vascular plants, gymnosperms and angiosperms. The functions are transport, excretion, respiration, regulation, nutrition, synthesis, reproduction, and growth and development.

The functions are described as:

• Transport- how organisms get what they need to cells; how they move waste from cells to organs of excretion.
• Excretion- how organisms get rid of their waste and balance their fluids (pH, salt concentration, water).
• Regulation- how organisms control body processes - hormones, nervous system.
• Respiration- how organisms get oxygen from the environment get oxygen from the environment and release carbon dioxide back to the environment and how plants exchange gases.
• Nutrition- how organisms break down and absorb foods.
• Synthesis- how organisms build necessary molecules.
• Reproduction- sexual versus asexual, eggs, seeds, spores, placental, types of fertilization.
• Growth and development- metamorphosis, development in egg or in uterus, growth from seed or spore.

Thursday- Today we had a sub and completed our chart using the textbook.

Friday- Today we watched the "March of the Penguins" and analyzed the movie to determine how Penguins accomplish essential life functions including: transport, excretion, respiration, regulation, nutrition, synthesis, reproduction, and growth and development.