tara record in Sessil recording can be imprecise miskadling eally more accurate
ID: 134464 • Letter: T
Question
tara record in Sessil recording can be imprecise miskadling eally more accurate thon evolutionary diversity studies w/ specic S be luhy dots Posil record appear ta houre grtater diversity in more re cent rocks, comparedl to older rocks L speculation s C. why do masine animals wl harol bodly parts hovc higher represendtations thon land animals wl hard los dy parts ZSpeculotions d. Explain the ias in thre Rassil recardl QaRritten towordl Eyplain non Scienthic audlience. Discues bias in Poss il recordl Sources, Wh be overcome exist, s how bias is atempted taExplanation / Answer
a) Species are normally considered to be the fundamental unit for understanding the evolution of biodiversity. Yet, in a survey of botanists in 1940, twice as many felt that plant genera were more natural units than plant species. Revisiting the survey, we found more people now regarded species as a more evolutionarily real unit, but a sizeable number still felt that genera were more evolutionarily real than species.
b)The Fossil Record Shows Mass Extinctions. When organisms die, sometimes their remains are preserved as fossils. Determining the ages of these fossils provides a record of the organisms that lived during different periods of Earth's history.
c)Seawater is much denser than air – as a result, there are vast numbers of microscopic organisms suspended in it. Cockles, as well as many other bivalves, are filter feeders. They have adapted specialised siphon structures to filter these organisms and any other particles of food from the surrounding water
Although dolphins can avoid the bends, they are not immune to it. ... If divers ascend too quickly, the dissolved nitrogen forms bubbles in the body, causing decompression sickness. But marine mammals such as whales, dolphins, and seals are highly adept at dealing with the pressures of the deep.
Many marine organisms--such as coral, clams, mussels, sea urchins, barnacles, and certain microscopic plankton--rely on equilibrated chemical conditions and pH levels in the ocean to build their calcium-based shells and other structures.
d) Biases in the Fossil Record. - Preservation Potential. The geological record of life on Earth, that is the fossil record, is not a fair sample of the life that existed in the past. This is because fossilisation favours certain organisms in certain environments over others.
Animals with hard parts are obviously more likely to be preserved than those that have only soft bodies. Animals may have hard parts, but if they are fragile (perhaps thin), they will not preserve as well as those that have more resistant structure.
Avoiding bias. To minimize the role of subjective judgments in making the measurements, the data on snail sizes were obtained using a consistent method for measuring the shells. In addition, the researchers who collected the snail data sometimes ran into a problem: too many fossils. Some snail species were represented by so many specimens that it would have been too time consuming to measure all the adults. How did they decide which specimens to measure? If the specimens had been hand-picked for measurement, the person selecting the snails could have biased the sample toward larger or smaller snails. Instead, the researchers identified a random subset for measurement so that personal bias couldn't skew the data. The researchers reasoned that this random subset would likely provide a representative sample of all the specimens of that species.
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