Sarfati tags the following comment on to the end of his paragraph on the floras of Eastern Asia and Eastern North America, I think to make the point that all plant species around the world can only have been there for a maximum of 4,500 years (following Noah's flood):
Indeed, many of our crop plants can be traced back to the 'Fertile Crescent' – the plain of Shinar – consistent with the biblical account of human dispersion from Babel, bringing along their plants (and domestic cats). [Page 174]Crop plant domestication is thought to have occurred independently and almost simultaneously in several places around the world.[footnote 1] A Fertile Crescent origin is true for wheat, barley, lentil, chickpea, pea, vetch and flax. But many crop plants did not originate in the Fertile Crescent. Maize, potato, sweet potato and cassava come from Central and South America; rice, soy bean, and foxtail millet from China; pearl millet and probably sorghum from sub-Saharan Africa; and broomcorn millet from Central Asia. Other crops that didn't originate in the Fertile Crescent include yam, taro, squash, plantain, quinoa, squash, and the common bean. These multiple centres of crop origin don't discount the Babel story outright (whether the story should be interpreted as historical narrative is a whole other discussion), but neither do they match a strict young-Earth timeframe.
Sarfati wraps up his discussion on biogeographical anomalies with some sweeping statements that aren't supported by the references he cites. He starts off reasonably well, pointing out that explanations for the disjunct species shared by Africa and South America tend to invoke either a crossing of the Atlantic Ocean or a long migration via joined-up land to the north. His reference here is a 2002 paper by Charles Davis, et al, that argues the Malpighiaceae family of plants (found in Africa and South America) migrated from northern South America to North America and Europe (which were joined), and then on to Africa. This "Laurasian migration route" occurred "during episodes starting in the Eocene [56 to 34 million years ago], when climates supported tropical forests". So far, so good. But then Sarfati says:
Indeed, to 'explain' whether faunas are shared or not between Africa and South America, evolutionists resort to ad hoc openings and closings of the Laurasian route, which show how plastic evolutionary theory can be.[Page 174]Sarfati again references Davis' 2002 paper – this time a specific citation in Davis' paper of a 2001 paper by S Renner, G Clausing and K Meyer. The 2001 paper is about the distribution of the Melastomataceae family of plants. Davis cites this paper as an example of other plants appearing to have spread from South America to Africa through the Laurasian route during the Eocene.
Neither the Davis nor the Renner paper makes any reference to faunas. Perhaps Sarfati simply made a mistake and he meant to say 'floras', not 'faunas'. But I also can't see anything in either paper to support his claim they rely on "ad hoc" openings and closings of the Laurasian route. Both papers refer to specific instances when the Laurasian route would have supported the migration of floras (such as the "Eocene climate optimum", when the warmer climate meant tropical forests were present in higher latitudes and land bridges joined the northern land masses). These are not ad hoc claims – they are supported by genetic analysis of plants, and studies of the fossil record, geology and the ancient climate. Naturally young-Earth creationists reject this kind of evidence when it doesn't suit their arguments. Indeed, looking at some of the young-Earth creationist literature on migration routes and land bridges, you could make a case that young-Earth creationists are the ones resorting to "ad hoc" claims to fit their "plastic" theories.
The fossil record also presents problems for evolutionary explanations of biogeography. For example, there are many similar plant fossils in western North America and eastern Asia, yet the evolutionary timescale 'dates' them to a time when Alaska and Russia still had thousands of miles of ocean between them. [Page 175]Here Sarfati gives a reference to a paper by geologist Charles Smiley from a book published in 1976. Smiley's paper documented distribution patterns of plant fossils in the Beringian region (areas of modern-day Alaska and eastern Siberia around the Bering Strait) from the later Paleozoic (around 350-250 million years ago) and Mesozoic (around 250-66 million years ago) and showed they did not match the latest models for continental drift, which drew on the new theory of plate tectonics. He concluded:
The geometry of recognized floral provinces does not always coincide with the global geometry that is postulated in current models of continental drift...The evidence of floral interchange between Eurasia and western North America implies the presence of a land dispersal route across the Beringian region at least from later Paleozoic time. But plate tectonics theory requires an oceanic separation perhaps thousands of kilometers wide through this region prior to the Cenozoic [66 million years ago].So Smiley believed the fossil record suggested there was a land bridge between Alaska and Siberia that existed as far back as the later Paleozoic, but some models of plate tectonics said these regions were separated by an ocean at that time. It's important to remember the theory of plate tectonics was still in its infant stage in the early 1970s (it had only emerged as a unified theory in the late 1960s) and there wasn't yet agreement on all aspects of the models criticised by Smiley. For instance, a 1975 paper by zoologist David Gaskin saw things quite differently, noting "There is good geological evidence [the] Bering Strait closed periodically during the Cretaceous [145-66 million years ago] and Tertiary [65-2.6 million years ago]".
More recent papers suggest there is now greater agreement that Beringian land bridges existed much further in the past (perhaps that's why Sarfati is referencing such an old paper, rather than anything published in the last 35 years). For example, a 2012 paper focusing on the Eocene notes the Beringian land bridge was already in place at the beginning of this period. And a 2011 paper describes how the dinosaur fossil record in Asia and western North America supports the mounting evidence that a Beringian land bridge existed at least 108 million years ago, to the Early Cretaceous. This is still not as far as Smiley would have liked. There may well be other papers demonstrating land bridges at even earlier periods, but I haven’t been able to find them.
 I Usha Rao and B K Pandey, 'Origin and Introduction of Crop Plants, Cereals, and Pulses' (2007) http://nsdl.niscair.res.in/
 Daniel Zohary, Maria Hopf and Ehud Weiss, Domestication of Plants in the Old World: The Origin and Spread of Domesticated Plants in Southwest Asia, Europe, and the Mediterranean Basin, Oxford University Press (2012: fourth edition).
 Dolores Piperno, et al, 'Starch grain and phytolith evidence for early ninth millennium B.P. maize from the Central Balsas River Valley, Mexico', Proceedings of the National Academy of Sciences, Vol 106, No 13 (2009), pp 5019-24; online at: http://www.pnas.org/content/
 D Spooner, et al, 'A single domestication for potato based on multilocus amplified fragment length polymorphism genotyping', Proceedings of the National Academy of Sciences, Vol 102, No 41 (2005), pp 14694-9; online at: http://www.pnas.org/content/
 'Sweet Potato (Ipomoea batatas)' (2012) http://libweb.hawaii.edu/
 K Olsen and B Schaal, 'Evidence on the origin of cassava: phylogeography of Manihot esculenta', Proceedings of the National Academy of Sciences, Vol 96, No 10 (1999), pp 5586-91; online at: http://www.pnas.org/content/
 Jeanmaire Molinaa, et al, 'Molecular evidence for a single evolutionary origin of domesticated rice', Proceedings of the National Academy of Sciences, Vol 108, No 20 (2011), p 8351; online at: http://www.pnas.org/content/
 Li-Juan Qiu and Ru-Zhen Chang, 'The Origin and History of Soybean', Guriqbal Singh (ed), The Soybean: Botany, Production and Uses, Wallingford: CAB International (2010), pp 1-23.
 Zohary, Hopf and Weiss, pp 8, 20, 69, 71, 72-3.
 Rao and Pandey.
 Charles Davis, et al, 'Laurasian migration explains Gondwanan disjunctions: evidence from Malpighiaceae', Proceedings of the National Academy of Sciences, Vol 99, No 10 (2002), pp 6833-7; online at: http://www.pnas.org/content/
 S Renner, G Clausing and K Meyer, 'Historical biogeography of Melastomataceae: the roles of Tertiary migration and long-distance dispersal', American Journal of Botany, Vol 88, No 7 (2001), pp 1290-1300; online at: http://www.amjbot.org/content/
 See, for example: Dominic Statham, 'Migration after the Flood' (12 March 2013) http://creation.com/Flood-
 Charles Smiley, 'Pre-Tertiary Phytogeography and Continental Drift – Some Apparent Discrepancies', in J Gray and A J Boucot (eds), Historical Biogeography, Plate Tectonics and the Changing Environment, Corvallis: Oregon State University Press, pp 311-319.
 David E Gaskin, 'Revision of New Zealand Crambini (Lepidoptera: Pyralidae: Crambinae)', New Zealand Journal of Zoology, Vol 2, No 3 (1975), p 273.
 Jaelyn Eberle and David Greenwood, 'Life at the top of the greenhouse Eocene world - A review of the Eocene flora and vertebrate fauna from Canada's High Arctic', GSA Bulletin, Vol 124, No 1/2 (2012), p 7; online at: http://geode.colorado.edu/~
 Lindsay Zanno and Peter Makovicky, 'On the earliest record of Cretaceous tyrannosauroids in western North America: implications for an Early Cretaceous Laurasian interchange event', Historical Biology, (24 February 2011), p 1-9