Recent Evolution in Humans Evolution is very much still happening today and its happening to us Right here right now Our genes constantly change over time thanks to the power of selection ID: 779134
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Slide1
Evolution – the genetic change in a species over time
Slide2Recent Evolution in Humans
Evolution is very much still happening today — and it's happening to us.
Right here, right now.
Our genes constantly change over time thanks to the power of selection.
Slide3Recent Evolution in Humans
1. Drinking milk as adults
All mammals (besides humans) stop producing lactase after weaning.
Lactase is needed to breakdown lactose (milk sugar) in the body.
This means that they will no longer be able to digest milk when they get older.
Slide4Recent Evolution in Humans
1. Drinking milk as adults
Scientists have discovered a mutation that first appeared on the plains of Hungary about 7,500 years ago, that allowed some humans to digest milk into adulthood.
The ability to digest protein-rich, calorie-dense, dairy products was a definite evolutionary advantage.
Slide5Recent Evolution in Humans
1. Drinking milk
as adults
We still see evidence of this genetic change today.
This is why more than 75% of humans are lactose intolerant.
Slide62. Disease resistance
Any genetic mutation that leads to an advantage for survival, will continue in future generations.
Sickle-Cell Anemia prevents Malaria.
Sickle-Cell Anemia is most common in people of African descent (7%), and other areas where malaria is prevalent.
Slide72. Disease resistance
About 10% of Europeans have a genetic mutation that protects them from HIV infection.
This genetic mutation (known as CCR5-Ä32) prevents the virus from entering the cells .
13 People Identified As Immune To Genetic Diseases, But Researchers Can't Find Them
http://www.iflscience.com/health-and-medicine/thirteen-people-identified-immune-genetic-diseases-researchers-cant-trace-them/
http://what-when-how.com/acp-medicine/hiv-and-aids-part-2/
Slide8Blue Eyes - a Mutation
New research shows that people with blue eyes have a single, common ancestor.
Scientists have tracked down a genetic mutation which took place 6,000-10,000 years ago and is the cause of the eye color of all blue-eyed people.
Slide9Blue Eyes - a Mutation
"Originally, we all had brown eyes," said Professor Hans
Eiberg
from the Department of Cellular and Molecular Medicine. "But a genetic mutation affecting the OCA2 gene in our chromosomes resulted in the creation of a "switch," which literally "turned off" the ability to produce brown eyes.“
Slide10Super Site
An unknown number of women may perceive millions of colors invisible to the rest of us.
Slide11Blue Eyes - a Mutation
This affectively varied the amount of melanin produced by the eye.
Slide12Breathing at High Altitudes
Indigenous Tibetans, who live at altitudes above 10,000 feet in the Himalayan highlands, have blood that produces more of the oxygen-transporting hemoglobin protein.
Slide13Blind Cave Fish and Deep Sea Creatures
Named for the feature that it lacks: eyes. Originally from deep caves in Mexico, it has no need for eyesight.
It uses sonar and other heightened senses to navigate and to avoid bumping into other fish.
https://www.youtube.com/watch?v=Sd7lvPpDDUg
https://www.youtube.com/watch?v=YVvn8dpSAt0
HELP!
I CAN’T SEE!!
Slide14Blind Cave Fish and Deep Sea Creatures
Named for the feature that it lacks: eyes. Originally from deep caves in Mexico, it has no need for eyesight.
It uses sonar and other heightened senses to navigate and to avoid bumping into other fish.
https://www.youtube.com/watch?v=Sd7lvPpDDUg
https://www.youtube.com/watch?v=YVvn8dpSAt0
HELP!
I CAN’T SEE!!
Slide15Wisdom Teeth
Many people are born without wisdom teeth.
A few
thousand
years ago, a mutation popped up that prevented wisdom teeth from growing at all. Now one in four people are missing at least one wisdom tooth.
Slide16Wisdom Teeth
Humans stopped needing wisdom teeth after humans begin
cooking
food and developed agriculture thousands of years ago.
This switch to softer foods, decreased the size of our jaw muscles.
Cave men would wear out their molars and have room for the wisdom teeth to replace the.
Most people don’t have room for them.
Slide17Shrinking Brains
We think pretty highly of our brains, but it turns out they've actually been shrinking for more than 20,000 years.
The total change adds up to a piece the size of a tennis ball in an adult male.
Slide18Vestigial Traits
We all have traits or behaviors that suited our ancestors just fine, but no longer make any sense — but we just can't seem to get rid of them.
The Appendix -
once aided our primate ancestors with the digestion of cellulose-rich plants once aided our primate ancestors with the digestion of cellulose-rich plants
Your coccyx, better known as your tailbone, is the very last part of your vertebrae, and is the remnant of a lost tail.
Slide19Arrector
Pili (
goose bumps)
“When you're cold or stressed out, your
arrector
pili are the smooth muscle fibers that contract involuntarily to give you "goose bumps."
this can provide warmth
This can make you look bigger
No longer makes sense for us to have.
http://io9.gizmodo.com/5829687/10-vestigial-traits-you-didnt-know-you-had
Slide20Plato (428-348 BC) on Evolution
Plato believed that the structure and form of organisms could be understood from their function.
He believed the function of the organism was designed to achieve ultimate goodness and harmony.
I’m HUNGRY!!
Slide21Aristotle (the father of biology)on Evolution
Aristotle (384-322 BC)
Aristotle, was the first to come up with the idea of evolution.
His idea was that organisms changed over time striving toward what he called “the
telos” (
an ultimate object or aim).
Slide22Aristotle
(the father of biology)
on Evolution
- the "scale of nature"
Rocks and Minerals
Plants
Jellyfish
Insects
Fish
Reptiles
Birds
Mammals
Humans
Develop a "scale of nature," in which he arranged the natural world on a ladder commencing with inanimate matter to plants, invertebrates, and vertebrates.
Among the vertebrates, he placed the fish at the lowest rung of the ladder and humans on the highest rung. This "scale of nature" represents a progression from the most imperfect to the most perfect.
Slide23Goethe (1749-1832),
Goethe (1749-1832) believed that the origin of each level of organism was based on a fundamental “primitive plan” from which the more complex features and organisms developed.
https://en.wikipedia.org/wiki/Evolution_of_biological_complexity
Slide24Natural Selection
Darwin proposed that inherited traits that were advantageous to survival, had a higher probability of being propagated to future generations.
The result would be adaptation, evolutionary modification of a population that improves each individuals’ chances of survival and reproductive success in the environment occupied by the population.
Slide25Natural Selection
The trait that that increases the survival of that species that evolved over generations is called an ADAPTATION.
https://www.youtube.com/watch?v=YVvn8dpSAt0
http://listverse.com/2014/03/18/10-totally-weird-creature-adaptations/
Slide26Evolution by Natural
Selection
As a result of natural selection, the population changes over time; the frequency of favorable traits increases in successive generations, and unfavorable traits decrease or disappear.
1800 moths in London - video
https://www.youtube.com/watch?v=aTftyFboC_M
Slide27Evolution by natural selection results from four natural conditions:
#1
High reproductive capacity.
Each species produces more
offspring than will survive to maturity.
Slide28Evolution by natural selection results from four natural conditions:
#2
#2 Heritable variation.
The individuals in a population exhibit variation.
Some traits improve the chances of an individual’s survival and reproductive success.
The variation necessary for evolution by natural selection must be inherited so that it can be passed to offspring.
Slide29Evolution by natural selection results from four natural conditions:
#3
Limits on population growth, or a struggle for existence.
Only so much food, water, light, growing space, and so on are
available to a population, and organisms compete with one
another for the limited resources available to them.
Other limits on population growth include predators and diseases.
Slide30Evolution by natural selection results from four natural conditions:
#4
Differential reproductive success.
Reproduction is the key to natural selection:
The best-adapted individuals reproduce most successfully, whereas less fit individuals die prematurely or produce fewer or less viable offspring.
In some cases, enough changes may accumulate over time in geographically separated populations (often with slightly different environments) to produce new species.
Slide31Charles Darwin
Charles Darwin visited the Galápagos Islands off the coast of Ecuador.
Among the species he studied, he studied 14 different finch species found on the island.
Each finch species was unique with special adaptations that helped it survive it its environment.
These adaptive traits were different from finches living on the South American mainland.
Slide32Charles Darwin
The finch species, although similar in color and overall size, exhibit remarkable variation in the shape and size of their beaks, which are used to feed on a variety of foods.
Darwin realized that the 14 species of Galápagos finches descended from a single common ancestor—one or a small population of finches that originally colonized the Galápagos from the South American mainland. Over many generations, the surviving finch populations underwent natural selection, making them better adapted to their environments, including feeding on specific food sources. The evolution of these finches continues to be actively studied by researchers.
Slide33Darwin’s Finches
Each species’ beak was specially adapted to find and eat a specific diet.
Slide34Trying to Organize Organisms
Until the invention of the microscope in late 1590’s (by Zacharias (son) and Hans (father) Jansen), scientists thought there were only 2 broad categories of organisms on Earth; 1) Plants and, 2) Animals.
Scientists had to rethink this idea when they discovered bacteria (prokaryotic cells). Bacteria were distinctly different and separate from plant or animal cells.
Bacteria have a prokaryotic cell structure: They lack organelles enclosed by membranes, including a nucleus.
Slide35There are 2 sub-divisions of prokaryotes
The prokaryotes fall into two groups that are sufficiently distinct from each other to be classified into two kingdoms, Archaea and Bacteria.
The archaea frequently live in
oxygendeficient
environments and are often adapted to harsh conditions; these include hot springs (like Old Faithful, at Yellowstone), salt ponds, and hydrothermal vents
Raven, Peter H.; Hassenzahl, David M.; Hager, Mary Catherine; Gift, Nancy Y.. Environment, 9th Edition (Page 86). Wiley. Kindle Edition.
Slide36There are 2 sub-divisions of prokaryotes
The archaea frequently live in oxygen-deficient environments and are often adapted to harsh conditions; these include hot springs (like Old Faithful, at Yellowstone), salt ponds, and hydrothermal vents (see Case in Point: Life Without the Sun, in Chapter 3).
The thousands of remaining kinds of prokaryotes are collectively called bacteria.
Slide37Eukaryotes
The eukaryotes, organisms with eukaryotic cells.
Are divided into four kingdoms of living things,
1) plants,
2) animals,
3) protists, and 4) fungi,
Slide38Eukaryotes
Eukaryotes are made up of eukaryotic cells
Eukaryotic cells
1) Have a nucleus
2) Membrane-bound organelles (compartmentalization)
3) Are highly structured Are divided into four kingdoms of living things, 1) plants2) animals
3) protists4) fungi
Slide39Eukaryotes
Are divided into four kingdoms of living things,
1) plants - photosynthesis
2) animals – ingest food and digest it
in their
bodies. 3) protists (Unicellular or relatively simple multicellular eukaryotes, such as algae, protozoa, slime molds, and water molds, are classified as members of the kingdom Protista.4) fungi (molds and yeast) - secrete digestive enzymes into their food and then absorb the predigested nutrients.
Slide40Slide41Now on to
population ecology
Slide42Play the Survival Game
http://www.sciencechannel.com/games-and-interactives/charles-darwin-game/