{"id":6197,"date":"2011-06-18T09:20:35","date_gmt":"2011-06-18T16:20:35","guid":{"rendered":"https:\/\/www.orthodoxytoday.org\/blog\/?p=6197"},"modified":"2011-06-18T09:20:35","modified_gmt":"2011-06-18T16:20:35","slug":"the-cost-of-adaptations-limits-evolution","status":"publish","type":"post","link":"https:\/\/www.orthodoxytoday.org\/blog\/2011\/06\/the-cost-of-adaptations-limits-evolution\/","title":{"rendered":"The Cost of Adaptations Limits Evolution"},"content":{"rendered":"<p><img loading=\"lazy\" decoding=\"async\" class=\"alignright size-full wp-image-6198\" title=\"Bacteria_01_200px\" src=\"https:\/\/www.orthodoxytoday.org\/blog\/wp-content\/uploads\/2011\/06\/Bacteria_01_200px.jpg\" alt=\"Bacteria Limited in Evolution\" hspace=\"9\" width=\"200\" height=\"170\" \/>by Brian Thomas, M.S. &#8211;<br \/>\nLiving forms supposedly evolved by adapting to environmental challenges. It is generally assumed that they did this by gradually acquiring the needed genetic mutations until brand new features arose and whole creatures eventually morphed into totally different ones. But does real science support this story?<\/p>\n<p>Experiments with bacteria continue to show that although adaptations  do occur, they are bound by hard limits to how much change can take  place.<sup>1<\/sup> And these limits also circumscribe evolution\u2019s potential.<\/p>\n<p>Two separate studies in the June 3, 2011, issue of <em>Science<\/em> arrived at the same conclusion. One tested the effects of multiple  mutations on the \u201cfitness\u201d of mutant versions of a methanol-eating  bacteria called <em>Methylobacterium<\/em>.<sup>2<\/sup> Researchers  measured the relative fitness of a mutant by directly comparing its  growth rate with non-mutants in the limited resource environment to  which the mutants had adapted. <!--more--><\/p>\n<p>When placed in a challenging environment, bacteria at first rapidly  adapt their chemistry by generating \u201cmutations\u201d that can help them  adjust to their new surroundings. But over time, fewer adaptive changes  occur. The second study showed the effects of multiple mutations on the  fitness of the common gut bacteria <em>Escherichia coli<\/em>.<sup>3<\/sup> The results indicated that each additional mutation was less helpful for the creature\u2019s attempts to adapt.<\/p>\n<p>These researchers may even have discovered why the pace of adaptations decelerates over time. The technical paper for the <em>Methylobacterium<\/em> study, steered by senior author and Harvard evolutionary biologist  Christopher Marx, stated, \u201cProportional reductions of a cost became  successively less beneficial as the cost itself was alleviated.\u201d<sup>2<\/sup><\/p>\n<p>So, the changes in bacterial DNA came with a cost. The mutant  bacteria had to spend extra cellular energy to regulate protein  production. As the bacteria gained control of the pace of protein  production, fewer adaptations were generated.<\/p>\n<p>Marx\u2019s paper also cited a third study, published in the journal <em>PLoS Genetics,<\/em> in which \u201cadaptive mutations\u201d in baker\u2019s yeast also brought diminishing returns.<sup>4<\/sup><\/p>\n<p>But if adaptation rates slow over time, then why didn\u2019t the process  of generating adaptations grind to a halt long ago? In order for  big-picture evolution to work, adaptation rates should at least be  constant, if not increasing, instead of decreasing. In other words,  adaptations are going the wrong direction.<\/p>\n<p>This principle of diminishing returns with genetic modifications  limits the potential for change. Those committed to the Darwinian  paradigm of unlimited biological change do not generally refer to any  \u201climitations\u201d such as this. But the <em>Methylobacterium<\/em> authors,  to their credit, stated that these \u201ctrends in genetic  interactions\u2026affect both the speed of adaptation and the degree to which  possible trajectories are limited.\u201d<sup>2<\/sup><\/p>\n<p>And the observed limits on adaptations also limit the \u201cpossible  trajectories\u201d of change to those that occur strictly within a created  kind, according to observations. After all, both the bacteria and the  yeast remained the same species, even after thousands of generations.  And their incredible abilities, limited though they may be, to alter  their own genetic code in order to adapt to new environments are  certainly the products of purposeful creation.<\/p>\n<p><em><strong>References<\/strong><\/em><\/p>\n<ol>\n<li>Anderson, K. L. and G. Purdom. 2008. <a href=\"http:\/\/www.answersingenesis.org\/articles\/aid\/v4\/n1\/beneficial-mutations-in-bacteria\" target=\"_blank\">A Creationist Perspective of Beneficial Mutations in Bacteria<\/a>. <em>Proceedings of the Sixth International Conference on Creationism<\/em>. Pittsburgh PA: Creation Science Fellowship and Dallas, TX: Institute for Creation Research, 73-86.<\/li>\n<li>Chou, H.-H. et al. 2011. Diminishing Returns Epistasis Among Beneficial Mutations Decelerates Adaptation. <em>Science<\/em>. 332 (6034): 1190-1192.<\/li>\n<li>Khan, A. I. et al. 2011. Negative Epistasis Between Beneficial Mutations in an Evolving Bacterial Population. <em>Science<\/em>. 332 (6034): 1193-1196.<\/li>\n<li>Kvitek, D. J. and G. Sherlock. 2011. <a href=\"http:\/\/www.plosgenetics.org\/article\/info%3Adoi%2F10.1371%2Fjournal.pgen.1002056\" target=\"_blank\">Reciprocal Sign Epistasis between Frequently Experimentally Evolved Adaptive Mutations Causes a Rugged Fitness Landscape<\/a>. <em>PLoS Genetics<\/em>. 7 (4): e1002056.<\/li>\n<\/ol>\n<p>HT: <a href=\"http:\/\/www.icr.org\/article\/6206\/\" target=\"_blank\">ICR.org<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>by Brian Thomas, M.S. &#8211; Living forms supposedly evolved by adapting to environmental challenges. It is generally assumed that they did this by gradually acquiring the needed genetic mutations until brand new features arose and whole creatures eventually morphed into totally different ones. But does real science support this story? Experiments with bacteria continue to &#8230; <a title=\"The Cost of Adaptations Limits Evolution\" class=\"read-more\" href=\"https:\/\/www.orthodoxytoday.org\/blog\/2011\/06\/the-cost-of-adaptations-limits-evolution\/\" aria-label=\"Read more about The Cost of Adaptations Limits Evolution\">Read more<\/a><\/p>\n","protected":false},"author":497,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"generate_page_header":"","footnotes":""},"categories":[11,51],"tags":[],"class_list":["post-6197","post","type-post","status-publish","format-standard","hentry","category-intelligent-design","category-science"],"_links":{"self":[{"href":"https:\/\/www.orthodoxytoday.org\/blog\/wp-json\/wp\/v2\/posts\/6197","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.orthodoxytoday.org\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.orthodoxytoday.org\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.orthodoxytoday.org\/blog\/wp-json\/wp\/v2\/users\/497"}],"replies":[{"embeddable":true,"href":"https:\/\/www.orthodoxytoday.org\/blog\/wp-json\/wp\/v2\/comments?post=6197"}],"version-history":[{"count":0,"href":"https:\/\/www.orthodoxytoday.org\/blog\/wp-json\/wp\/v2\/posts\/6197\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.orthodoxytoday.org\/blog\/wp-json\/wp\/v2\/media?parent=6197"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.orthodoxytoday.org\/blog\/wp-json\/wp\/v2\/categories?post=6197"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.orthodoxytoday.org\/blog\/wp-json\/wp\/v2\/tags?post=6197"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}