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Welcome to YOUR AP Biology Blog
This Blog is designed for you! A place where you can find information to help you be successful in AP Biology. Help on specific assignments, labs, or even quiz preparation will be provided here.
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Helpful Reads
- "The Seven Daughters of Eve" Brian Sykes
- "The Hot Zone" Richard Preston
- "What is Evolution" Ernst Mayr
- "The Monk in the Garden" Robin Henig
- Anything by Richard Dawkins
- Anything by Stephen Jay Gould
- "The Third Chimpanzee: The Evolution and Future of the Human Animal" Jared Diamond
- "Silent Spring" Rachel Carson
- "Origin of Species" Charles Darwin
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rmcminn@usd259.net
Slime Mold is a Master Network Engingeer
ReplyDeleteIn a recent study, a japanese scientist places oat flakes, a favorite food of slime molds, in a pattern resembling populations centers around Tokyo. Then, the slime mold was allowed to ingest the oat flakes, creating a system of "nutrient tubes" between each oat flake. The scientist mapped the tunnels between each oat flake, and compared his map to a map of mass transit systems in and around Tokyo, and the results were very similair. What took engineers years to figure out took a slime mold less than a day. The slime mold, a unicellular protist, has no central intelligence. The slime mold's method was as follows: it created a fine mesh over the whole area, and eventually deleted redundant/ineffectual tunnels, and strengthened effective tunnels.
The findings were then translated into a mathmatical model, which can be used in future mass transit planning problems.
Cigarettes Might Be Infectious
ReplyDeleteBy: Janet Raloff
New studies find that the tobacco in cigarettes hold hundreds of different germs, and some of which are responsible for many human illnesses. Studies indicate that smoking renders people vulnerable to disease by impairing lung function and immunity. Amy Sapkota has done many studies on the germs in tobacco. In one of her studies she performed a series of tests on the leafy bits of a cigarette. In one study she isolated all of the ribosomal material and homed in on its long, species specific stretches known as 16S regions. Nearly 800 different types of bacteria lace this 16S region. Among these germs were: Campylobacter, which can cause food poisoning and Guillain-Barre Syndrome; Clostridium, which can cause food poinsoning and pneumonias; Corynebacterium, also associated with pneumonias and other diseases; E. coli; Klebsiella, Pseudomonas aeruginosa and Stenotrophomonas maltophilia, all of these are associated not only with pneumonia but also with urinary tract infections; and a number of Staphylococcus species that underlie the most common and serious hospital-associated infections. Many people are skeptical that as a cigarette burns, the bacteria will be killed in the process, but Sapkota is not sure that is true. Smoke particles may travel through the unburned part of the cigarette, pick up some germs and go into the lung, during a smoking session. Sapkota plans to study which type of tobacco are most likely to host viable germs, and whether those bacteria are transported into the body. When Sapkota began her tobacco work, 16S regions only screened for 700-odd species. But newer probes on the market can now host over 5000 germs. Newer probes seems to be increasing in bacteria.
By:Son Phan
ANCIENT DNA POINTS TO ADDITIONAL NEW WORLD MIGRATIONA
ReplyDelete-4,000-year-old Greenland man possessed close genetic ties to modern Siberians
By Bruce Bower
A 4,000-year-old Greenland man just entered the scientific debate over the origins of prehistoric populations in the Americas.
A nearly complete sequence of nuclear DNA extracted from strands of the long-dead man’s hair — the first such sequence obtained from an ancient person — highlights a previously unknown and relatively recent migration of northeastern Asians into the New World about 5,500 years ago, scientists say.
An analysis of differences, or mutations, at single base pairs on the ancient Greenlander’s nuclear genome indicates that his father’s ancestors came from northeastern Siberia, report geneticist Morten Rasmussen of the Natural History Museum of Denmark in Copenhagen and his colleagues in the Feb. 11 Nature. Three modern hunter-gatherer groups in that region — the Nganasans, Koryaks and Chukchis — display a closer genetic link to the Greenland individual than do Native American groups living in cold northern areas of North America, Rasmussen says.
A largely complete mitochondrial DNA sequence from the ancient man’s hair, extracted by the same researchers in 2008, places his maternal ancestry in northeastern Asia as well.
The team’s new comparative analysis of Inuk’s previously sequenced mitochondrial DNA indicates that the Saqqaqs diverged from their closest present-day relatives, Siberian Chukchis, an estimated 5,400 years ago. That calculation implies that ancestral Saqqaqs separated from their Asian relatives shortly before departing for the New World and rapidly traversing that continent to reach Greenland. No land bridge connected Asia to North America at that time, so migrants probably crossed the Bering Strait from what’s now Russia to Alaska by boat, Willerslev speculates.
His group also identified base pair patterns on Inuk’s nuclear DNA that are associated in modern populations with type A-positive blood and brown eyes, as well as thick, dark hair and large, flat front teeth typical of Asians and Native Americans. Inuk also possessed DNA signatures for an increased susceptibility to baldness, dry earwax characteristic of Asian populations, and a relatively slow metabolism and broad, short body commonly found in residents of cold climates.
DNA analyses of ancient humans and their ancestors usually face enormous technical challenges. Fossil bones get contaminated with the DNA of those who unearth these finds as well as with fungal and bacterial DNA. Measures to enrich ancient DNA include generating multiple samples of the same genetic sequences and isolating genetic fragments that show no signs of contamination.
Because DNA from hair contains little contamination from fungi or bacteria, Rasmussen’s team focused on Inuk’s locks. Frozen conditions following death also helped to preserve Inuk’s DNA and prevent significant contamination. The team generated 20 copies of his genome to confirm that significant contamination had not occurred.
Matt- I am now enlightened on how simple protists can help improve society.
ReplyDeleteJordan - Proof that asians immigrated that far west is amazing, and this find tells us much more about the phylogeny of humans.