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Biology 1002B Lecture Notes - Lecture 3: Binary Star, Hydrogen Bond

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School
Western University
Department
Biology
Course
Biology 1002B
Professor
Tom Haffie

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Document Summary

This lecture is going to focus on the galaxy, not the universe as a whole. Andromeda m31 another galaxy similar to the milky way: 100,000 light years across. Speed of light = 1. 1 billion km/h. Space travel not a feasible option in the near future. Only means by which to travel fast enough to reach the closet star and observe whether or not there is evidence of extraterrestrial life. Listening to other intelligent life forms-if there is intelligent life, we should be able to detect them by the radio waves they emit. Radio waves travel the speed of light, much faster than space shuttle. The drake equation for a galaxy not the universe. N = number of advanced civilizations in our galaxy. 100 billion stars (1011) (good estimate) in the milky way. Fp: 1011 x 0. 5 = 50 billion planets. Can we detect extrasolar planets: kepler mission. Trained on one specific part of the sky which encompasses about 150,000 stars.

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Related Questions

I've recently read a couple articles dealing with long term datastorage, and DNA was suggested as one of the prime candidates forlong term storage of digital data additionally, there is thisarticle which deals with decoding of long storage data. Thesepopular articles, though simple do mention important concepts- howpackets are stored in DNA use addressing schemes, redundancy ofstorage, writing for a recipient who may be using a differentlanguage, etc.

This made me think - we have the SETI initiative which islooking for signs of (intelligent) life in the universe. Thatorganization was created long time ago, and uses technologies ofthose days - radio waves. The modern science knows that we canstore a lot of data in DNA, and that most organism DNA containsonly a small fraction of protein coding sequences and a largeamount of non-coding material. If I understand correctly, some ofthe non coding material is repetitive and highly preserved. Hasanyone considered expanding the search for intelligent life toinclude examination of DNA for messages that might've been left byother intelligent species actually visiting earth?

I need help on this microbiology question:

Contrary to our favorite science fiction books and movies, the chances of us finding another planet with a civilization comparable to, or even more advanced than our own, seems highly unlikely. But, through your work as a microbiologist at NASA, you have been able to help change our views as to what forms of life we should be looking for on planets in our solar system and around neighboring stars. Instead of radio signals or errant transmissions, we have begun looking for planets that have environments similar to those capable of sustaining life as we know it here on Earth. To determine what we could find out there, you have begun studying different unique and atypical environments found here on Earth. Although the harsh conditions of hot springs or undersea sulfur vents seem incompatible with most forms of life, organisms known collectively as "extremophiles" have still managed to survive and adapt to these extreme conditions. You believe extremophiles may help you gain insight into the potential metabolic requirements, processes, and challenges of extraterrestrial life. Thus far in your search, you have identified some prokaryotic cells that have evolved to survive in the extreme conditions of sulfur vents on the sea floor. These vents are found at great depths, where the crushing pressure and lack of light and oxygen are prohibitive to many forms of life. Bacteria that are not considered extremophiles reside in most ecological niches on this planet. There are some common criteria for the environment that would sustain these bacteria. Availability of water, pH that lies between 5 and 9, temperatures that will remain steady and below boiling; these are some of the characteristics that bacteria will require in their environment if they are to succeed. But in the environment of the ocean floor vents, not only is the pH of the water very low, but also the water temperature is unusually high due to the geologic activity that fuels the vents. Organisms that are adapted to such harsh conditions have necessarily evolved enzymes able to function beyond average optima, as well as a chemosynthetic metabolism capable of using vent organic and inorganic compounds as energy sources.

Part A - Comparable Earth Environments to Be Found on Another Planet

You identify the prokaryotic cells you've found as a species of bacteria. These bacteria appear to be living off of nutrients and sulfur compounds released from the vents on the sea floor. Over time, the bacteria must have evolved extreme metabolic and enzymatic capabilities to allow them to tolerate and even benefit from the extreme depths, the lack of oxygen, the low pH of the surrounding waters, high temperatures due to volcanic releases, and the unique nutrient source of the vents.

Choose the characteristics and their impact on enzyme activity that are not correct from the following statements. (more than one may be chosen)

Archaea are able to tolerate highly acidic pH environments and have proteins that will not denature in the low-pH environments that the bacteria are found in.
Archaea are able to colonize water that is at or above the boiling temperature due to high levels of disulfide bridges that maintain the three-dimensional structure of the enzyme.
Archaea are only able to survive exceedingly well at high temperatures due to the amount of activation energy required by their enzymes.
Archaea are able to grow in extremely shady or low-light conditions that allow for optimal enzyme activity.

What exactly was Hooker's response to Darwin's, Origin of Species? Thank you for your help. I need help deciphering what his opinions truly were.

Hooker, J. D. 1859. [Review of] On the origin of species. Gardeners' Chronicle (31 December): 1052. Part 1.

From the above expressions it will be inferred that we have risen from the perusal of Mr. DARWIN'S book much impressed with its importance, and have moreover found it to be so dependent on the phenomena of horticultural operations, for its facts and results, and so full of experiments that may be repeated and discussed by intelligent gardeners, and of ideas that may sooner fructify in their minds than in those of any other class of naturalists, that we shall be doing them (and we hope also science) a service by dwelling in some detail upon its contents. Thus much we may premise, that it is a book teeming with deep thoughts on numberless simple and complex phenomena of life; that its premises in almost all cases appear to be correct; that its reasoning is apparently close and sound, its style clear, and we need hardly add its subject and manner equally attractive and agreeable; it is also a perfectly ingenuous book, bold in expressions as in thought where the author adduces what he considers clear evidence in his favour, frank in the statement of objections to the hypotheses or conclusions founded on its facts and reasonings; and uniformly courteous to antagonistic doctrines. In fine, whatever may be thought of Mr. DARWIN'S ultimate conclusions, it cannot be denied that it would be difficult in the whole range of the literature of science to find a book so exclusively devoted to the development of theoretical inquiries, which at the same time is throughout so full of conscientious care, so fair in argument, and so considerate in tone. . . . Hitherto most [naturalists] have, as we have already observed, contented themselves with the hypothesis that they were independently created, and the minority have clung to the only other explanation hitherto conceived, that they have all been created by variation from a single first-created living organism, or a few such. Now it must be borne in mind that both these views are mere hypotheses in a scientific point of view; neither has any inherent or prescriptive right to a preference in the mind of the impartial inquirer; but the most superficial observation will show that the hypothesis of original creations is incapable of absolute proof, except the operation be witnessed by credible naturalists, and can only be supported by facts that are either not conclusive against the opposite doctrine, or may be regarded as equally favourable to it; and this hypothesis is hence placed at a disadvantage in comparison with that of the creation of species by variation, which takes its stand on the familiar fact that species do depart from the likeness of their progenitors, both in a wild and domestic state. On the other hand the hypothesis of creation by variation labours under the disadvantage of being founded upon a series of phenomena, the action of each of which individually, as explained by Mr. DARWIN, would appear to prevent the possibility of species retaining their characters for any length of time, and it therefore appears at first sight opposed to the undisputed fact, that many hundreds of animals and plants have transmitted their characters unchanged (or nearly so) through countless generations, and covered, even within the historic period, many square miles of country each with millions of its exact counterpart. To explain this anomaly and to raise this hypothesis of creations by variation to the rank of a scientific theory, is the object of Mr. DARWIN'S book, and to do this he has endeavoured to invent and prove such an intelligible rationale of the operation of variation, as will account for many species having been developed from a few in strict adaptation to existing conditions, and to show good cause how these apparently fleeting changelings may by the operation of natural laws be so far fixed as to reconcile both the naturalist and the common observer to the idea, that what in all his experience are immutable forms of life may have once worn another guise. The hypothesis itself is a very old one; it was, as all the world knows, strongly advocated by LAMARCK, and later still by the author of the "Vestiges of the Natural History of the Creation," but neither of these authors were able to suggest even a plausible method according to which Nature might have proceeded in producing suitable varieties, getting rid of intermediate forms, and giving a temporary stability to such as are recognised as species by all observers. Mr. DARWIN has been more successful, though whether completely so or not the future alone can show. We shall proceed to examine his method in another article.