def remove_siblings(*args)
      options = args.extract_options!
      raise ArgumentError.new("Unknown option value: half: #{options[:half]}.") if (options[:half] and ![:father,:mother].include?(options[:half]))
      resulting_indivs = if args.blank?
        siblings(options)
      else
        args & siblings(options)
      end
      transaction do
        resulting_indivs.each do |sib|
          case options[:half]
          when :father
            sib.remove_father
            sib.remove_mother if options[:remove_other_parent] == true
          when :mother
            sib.remove_father if options[:remove_other_parent] == true
            sib.remove_mother
          when nil
            sib.remove_parents
          end
        end
      end
      !resulting_indivs.empty? #returned value must be true if self has at least a siblings to affect
    end
def remove_siblings(*args)
      options = args.extract_options!
      raise ArgumentError.new("Unknown option value: half: #{options[:half]}.") if (options[:half] and ![:father,:mother].include?(options[:half]))
      resulting_indivs = if args.blank?
        siblings(options)
      else
        args & siblings(options)
      end
      transaction do
        resulting_indivs.each do |sib|
          case options[:half]
          when :father
            sib.remove_father
            sib.remove_mother if options[:remove_other_parent] == true
          when :mother
            sib.remove_father if options[:remove_other_parent] == true
            sib.remove_mother
          when nil
            sib.remove_parents
          end
        end
      end
      !resulting_indivs.empty? #returned value must be true if self has at least a siblings to affect
    end
remove siblings by nullifying parents of passed individuals
 @overload remove_siblings(*siblings,options={})
   @param [Object] siblings list of siblings
   @param [Hash] options
   @option options [Symbol] half :father for paternal half siblings and :mother for maternal half siblings
   @option options [Boolean] remove_other_parent if specified, passed individuals' mother will also be nullified
 @return [Boolean] true if at least one sibling was affected, false otherwise