People who interpret the Bible literally may believe that a man named Noah collected all species of Earthly organisms on his ark. However, scientists no longer ask this question. Let me put the problem in a modern perspective by considering what it means to have animals from every species on an ark. Consider that siphonapterologists (experts in fleas) recognize 1,830 variety of fleas. Incredible as it may seem, there are around 300,000 species of beetles, making beetles one of the most diverse groups of organisms on earth. When biologist J.B.S. Haldane was asked by a religious person what message the Lord conveyed through His creations, he responded, "an inordinate fondness for beetles."
One of my favorite books on beetles is Ilkka Hanski's Dung Beetle Ecology, which points out that a large number (about 7000 species) of the 300,000 species of beetles live off animal dung. Did Noah bring these species on the ark? If he did, did he concern himself with the fact that animal dung is often fiercely contested. On the African savanna up to 4000 beetles have been observed to converge on 500 grams of fresh elephant dung within 15 minutes after it is deposited.
Did Noah or his family also take kleptoparastic beetles on the ark? These are dung beetles known to steal dung from others. Did Noah need to take into consideration that insect dung communities involve hundreds of complex ecological interactions between coprophagous flies and their parasites, insects, mites, and nematodes (an ecology probably difficult to manage on the ark!). In South Africa, more than 100 species of dung beetle occur together in a single cow pat. One gigantic species, Heliocopris dilloni resides exclusively in elephant dung. A few species of beetles are so specialized that they live close to the source of dung, in the hairs near an animal's anus.
You get my point! It's quite a mystery as to what the Biblical authors meant when they called for Noah taking pairs of every animal on the Earth. Incidentally, scientists very roughly estimate that the weight of animals in the hypothetical ark to be 1000 tons. You can use a value of 10 million for the number of species and assume an average mass of 100 grams. (Insects decrease this figure for average mass because of the huge number of insect species.) There would be some increase in mass if plants were used in the computation. (How would this change if extinct species were included?)
Even if Noah took ten or twenty of each kind of mammal, very few would be alive after a thousand years because approximately 50 individuals of a single species are needed to sustain genetic health. Any small population is subject to extinction from disease, environmental changes, and genetic risks — the gradual accumulation of traits with small but harmful effects. There is also the additional problem of making sure that there is both male and female offspring surviving. Today, species are considered endangered well before their numbers drop below fifty. (Interestingly, there's a conflicting Biblical description in the story of Noah that indicated God wanted Noah to take "seven pairs of clean animals... and a pair of the animals that are not clean... and seven pairs of the birds of the air also.")
The Biblical flood would probably kill most of the plant life on Earth. Even if the waters were to recede, the resultant salt deposits would prevent plants from growing for many years. Of additional concern is the ecological effect of the numerous dead carcasses caused by the initial flood.
Various authors have noted that if, in forty days and nights the highest mountains on Earth were covered, the required incredible rate of rain fall of fifteen feet per hour would sink the ark. All of these cogitations lead me to believe that most scientifically trained people no longer ask whether an actual man named Noah collected all species of Earthly organism on his ark. By extension, most scientifically trained people no longer ask if the Bible is literal truth.
CLIFF PICKOVER is author of over 20 books, his latest being Wonders ofNumbers: Adventures in Math, Mind, and Meaning. His web site, www.pickover.com, has received over 300,000 visits.