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WHY LINEAR #1. "The earliest protoeukaryotes may have had only one or a few linear chromosomes encompassing the entire genome (which also necessitated the evolution of centromeres and telomeres to allow faithful segregation and protect the ends from decay). Linear chromosomes are required because crossing over between two circular chromosomes generates a circular dicentric that is unstable (the chromosome is broken if the two centromeres attach to opposite spindle microtubules)." http://cshperspectives.cshlp.org/content/6/3/a016154.full View in LinkedIn

GROUP II INTRONS. "They can also spread through the genome by a similar, but less efficient reaction at ectopic sites. The phagocytosis of an α-proteobacterial cell by archaeal (or actinobacterial) eukaryotic precursor could have been accompanied by massive invasion of Group II introns." https://lnkd.in/d8Qr_bk View in LinkedIn

WHY LINEAR CHROMOSOMES? "There are several reasons to suggest that protoeukaryotes had linear chromosomes, or at least that these arose when meiosis evolved." https://lnkd.in/ebVhXPf View in LinkedIn

ANCESTRAL RETROTRANSPOSONS. "I propose that mobile Group II self-splicing elements (Group II introns) are a good candidate for the repeats that led to chromosome linearization. Group II introns are the proposed ancestors of introns and non-LTR retrotransposons." https://lnkd.in/d8Qr_bk View in LinkedIn

INFREQUENT EXAMPLES. "As logical as genomic streamlining might be, few examples have so far been found. Instead, a bevy of articles from the last 10 years show that three separate lines of evidence argue against widespread streamlining in prokaryotes." https://lnkd.in/d3Ys7Am View in LinkedIn

FLORAL TRANSFORMATIONS. "We have generated transgenic tobacco plants that ectopically express the AGAMOUS gene from Brassica napus, which is necessary for the C function. Flowers on the resulting plants showed homeotic transformations of sepals into carpels and petals into stamens." https://lnkd.in/dGN8Y2C View in LinkedIn

ABC FLORAL GENE SYSTEM. "Genetic studies suggest that three homeotic functions, designated A, B, and C, act alone and together to specify the fate of floral organ primordia in distantly related dicotyledonous plant species." https://lnkd.in/dGN8Y2C View in LinkedIn

FLOWERS AS MODIFIED LEAVES. "Goethe was right when he proposed that flowers are modified leaves. It seems that four genes involved in plant development must be expressed together to turn leaves into floral organs." https://lnkd.in/drsuFdW View in LinkedIn

FLOWER DIAGRAMS covering most types of flower structures, a thorough and advanced treatment. This is humbling to any non-specialist. https://lnkd.in/dtvUbfS View in LinkedIn

GUIDE TO FLORAL DIAGRAMS AND SYMBOLS. https://lnkd.in/dG89mnv View in LinkedIn